Did Paul Pray for Onesiphorus after he died?

One recent Roman Catholic claim is that Paul the apostle prayed for Onesiphorus after his death.  Unfortunately for Roman Catholic apologists, this claim is false.

There are two references to Onesiphorus in the New Testament, both of them in 2 Timothy.

2 Timothy 1:16-18 

The Lord give mercy unto the house of Onesiphorus; for he oft refreshed me, and was not ashamed of my chain: but, when he was in Rome, he sought me out very diligently, and found [me]. The Lord grant unto him that he may find mercy of the Lord in that day: and in how many things he ministered unto me at Ephesus, thou knowest very well.

2 Timothy 4:19 Salute Prisca and Aquila, and the household of Onesiphorus.

As you can see, there is no mention of Onesiphorus being dead. That does not conclude our discussion, because it might be asked: is it even a prayer for Onesiphorus?  It seems more like a blessing.  The same word (translated "give" in vss. 16 and 18) with the same inflection is found in three other places:

Romans 15:5 Now the God of patience and consolation grant you to be likeminded one toward another according to Christ Jesus:

2 Thessalonians 3:16 Now the Lord of peace himself give you peace always by all means. The Lord [be] with you all.

2 Timothy 2:7 Consider what I say; and the Lord give thee understanding in all things.

I take this to be a volitive optative, indicating a wish on the person's behalf.  The sense being something like, "I hope that the Lord gives ...."  Perhaps the line between blessing and prayer seems slim, and perhaps it is.  So, rather than belabor this particular aspect of the point, I'll leave it for others, and return to the bigger question, of why claim that Onesiphorus was dead?

This idea that he might be dead seems to stem from the absence of a specific greeting of Onesiphorus as distinct from a greeting to his house.  By contrast to the form of greeting given to Onesiphorus, we see the following:

• Romans 16:3-5 Greet Priscilla and Aquila my helpers in Christ Jesus: Who have for my life laid down their own necks: unto whom not only I give thanks, but also all the churches of the Gentiles. Likewise [greet] the church that is in their house. Salute my wellbeloved Epaenetus, who is the firstfruits of Achaia unto Christ.
• 1 Corinthians 16:19 The churches of Asia salute you. Aquila and Priscilla salute you much in the Lord, with the church that is in their house.
• Colossians 4:15 Salute the brethren which are in Laodicea, and Nymphas, and the church which is in his house.
• Philemon 1-2 Paul, a prisoner of Jesus Christ, and Timothy [our] brother, unto Philemon our dearly beloved, and fellowlabourer, And to [our] beloved Apphia, and Archippus our fellowsoldier, and to the church in thy house:

In these other cases, the greetings (Whether to or from) seem to be for the people and their house church, whereas for Onesiphorus, it seems to be only for his house church but not for Onesiphorus himself.  Additionally, the references to Onesiphorus's deeds are all in the aorist (i.e., they refer to past actions, nothing ongoing).  From these two observations, there is speculation that the absence of such a greeting indicates that Onesiphorus was now part of the great cloud of witnesses.  On the other hand, there are at least four other reasonable interpretations:

1. It may simply be that greeting the house church of Onesiphorus was meant to include the person whose house it was, namely Onesiphorus.  The advantage of this view is that it makes sense that it's still called his house, whereas it wouldn't be his house any more if he had already given up the ghost.  The sample size of other house church greetings is so small that it's risky to create a rigid rule from the four other examples (two of which relate, like this one, to Aquila and Priscilla).
2. It may be that Onesiphorus was the one hand-delivering the letter (2 Timothy) from Paul to Timothy. The advantage of this view is that it also helps to explain why Paul takes the time to mention Onesiphorus at both the beginning and ending of the letter. Another advantage is that does seem that Onesiphorus was with Paul both at Rome and also at Ephesus, suggesting that he may not have been already with Timothy when the letter was arriving.  
3. Related to the third hypothesis, Onesiphorus may have been engaged in missions work at the time, and consequently neither with Paul nor with Timothy at the time of writing the letter.  Onesiphorus had been assisting Paul both in Rome and in Ephesus, so the idea of him traveling at the time when Paul wrote to Timothy is not at all unreasonable.
4. A sadder option is that it may be that Onesiphorus was currently under church discipline, and consequently that he was temporarily not associated with his own house church.  The advantage of this view is that it helps explain the need for Paul's blessing of mercy on his behalf.  It also fits with the preceding context to the first mention of Onesiphorus' name:

2 Timothy 1:13-18 Hold fast the form of sound words, which thou hast heard of me, in faith and love which is in Christ Jesus. That good thing which was committed unto thee keep by the Holy Ghost which dwelleth in us. This thou knowest, that all they which are in Asia be turned away from me; of whom are Phygellus and Hermogenes. The Lord give mercy unto the house of Onesiphorus; for he oft refreshed me, and was not ashamed of my chain: But, when he was in Rome, he sought me out very diligently, and found [me]. The Lord grant unto him that he may find mercy of the Lord in that day: and in how many things he ministered unto me at Ephesus, thou knowest very well.

We do not see any such an interpretation in the early fathers or other early Christian (or even heretical) writers.  I mean, of course, that we do not see any indication of any need to explain why the greeting is for the household of Onesiphorus, and not Onesiphorus himself, nor any hint or suggestion that he had kicked the bucket.

Theodoret, Letters 97 and 123, mentions Onesiphorus without suggesting he was deceased. Augustine, Confessions Book XIII Chapter 25, speaks of Onesiphorus but does not tell us that he was amongst the departed. Chrysostom, Homily 3 on 2 Timothy, exegetes the text but makes no hint or suggestion that Onesiphorus has passed on.  Chrysostom also mentions Onesiphorus in his Homily in the Church of the Resurrection, but without any mention of Onesiphorus' dormition:

Therefore, as the word was running and piety being sown, fires and hatreds and wars were kindled on every side—not only against the teachers, but also against those being taught. 

For at the same time as anyone received the word, a common enemy went about against all; and he was driven out from his homeland, and was removed to exile, and was deprived of his property, and was endangered concerning his liberty—or rather, concerning life itself.

And at that time the tyranny of nature had no strength; but, as I have already said, children were despised, and brothers and relatives were in the rank of enemies, and together with the teachers the disciples suffered incurable things.

And showing these very things, Paul said: “For remember the former days, in which, having been enlightened, you endured a great struggle of sufferings—partly being made a spectacle by reproaches and afflictions, partly having become partners with those so treated. For you sympathized with the prisoners, and you accepted with joy the plundering of your possessions, knowing that you have a better and abiding possession in the heavens.”

And again, writing to the Thessalonians, he said: “For you became imitators, brothers, of the churches of God which are in Judea, because you also suffered the same things from your own countrymen, just as they also did from the Jews— those who even killed the Lord, and drove us out, and are opposed to all men.”

And again, writing to the Galatians, he said: “Did you suffer so many things in vain, if indeed it was in vain?”

And recounting his own sufferings, he said: “In much patience, in distress, in imprisonments, in labors, in watchings, in hunger, in thirst, and nakedness.”

And again: “Forty [lashes] minus one I received; three times I was beaten with rods; once I was stoned; a night and a day I have spent in the deep; in dangers of rivers, in dangers of robbers, in dangers from my own nation, in dangers in deserts.”

And again: “My daily assault, the anxiety for all the churches.”

And again: “The ethnarch of King Aretas was guarding the city of the Damascenes, wishing to seize me, and through a window I was let down in a basket through the wall and escaped his hands.”

And again elsewhere: “We were accounted as sheep for slaughter.”

And in another place again: “May the Lord grant mercy to the house of Onesiphorus, because he was not ashamed of my chain; but having come to Rome, he sought me very diligently and found me.”

Nor do we see the interpretation in other ancient Christian writers.  Origen, in De Principiis (Book III), Section 20 (21) (as also recorded in Philocalia, Chapter 21, Section 20), mentions Onesiphorus as an example of someone Paul praised, but without suggesting that Onesiphorus might have already expired. Tertullian's, On the Resurrection of the Flesh, is the most expected place to read of the notion that Onesiphorus had joined the celestial choir, but he sandwiches the reference in Chapter 23 to Onesiphorus between references to the Galatians themselves and Timothy, both of whom were evidently living groups at the time Paul wrote to them.  Thus, even though Tertullian sees "in that day" as pointing to a future bodily resurrection, he does not suggest that Onesiphorus received Paul's blessing after having left the land of the living.

Eusebius of Caesarea, in "Generalis elementaria introductio," or "General Elementary Introduction" (PG22, CPG3475 BP4), provides this reference that I could not find previously translated into English (with context): 

Chapter 5

The sun went forth upon the earth, and Lot entered into Segor. [TF: the LXX name for Zoar] And the Lord rained upon Sodom and Gomorrah brimstone and fire from the Lord out of heaven.

I do not think that any of those who have once believed that the Holy Scriptures are sacred and God-inspired would fabricate anything concerning these passages, attempting to contradict the things delivered concerning the Word of God—namely, that He also existed beforehand, having His own hypostasis, and that before the incarnation He accomplished the dispensations toward men. For the Scripture here clearly presents two Lords, if indeed “the Lord rained from the Lord.”

And a similar thing is found with the holy Apostle saying, “May the Lord grant mercy to the house of Onesiphorus; and may He grant him to find mercy from the Lord in that day.”

But indeed, in these matters, when setting forth words concerning the Father and the Son, assigning to the Unbegotten and Father of all both the lordship and authority over all things, and even over the Son Himself; and to the Word assigning the secondary position, after the Father, of rule and dominion over all things that have come into being.

And since here the Lord is twice named, in the phrase, “The Lord rained from the Lord,” twice also, according to the Hebrew and the Tetragrammaton, it is rendered— so that it is most plainly confessed that the reference is to two persons; and it is evident that this (refers) to God the Father of all and to His Word, that this ineffable indication is received, so that there is no longer any ambiguity, wherever such a title of God is found, that it is to be understood not only of the Unbegotten Nature, but also of the Word who in the beginning was with God.

While interesting (particularly in the appeal to the Hebrew and the use of the Tetragrammaton), it does not suggest that Onesiphorus was pushing up daisies whilst Paul was writing 2 Timothy.

Basil in his "Moral Rules" uses the passage from 2 Timothy to illustrate "That one ought not to abandon those who are struggling on behalf of piety," but does not comment in any way on the vital status of Onesiphorus.

Amphilochius of Iconium in Against the Heretics, section 18 writes (link to Andrew Jacobs' translation):

Where does your fixation with vessels come from? Out of what kind of tradition? Were the apostles, while they were preaching the Word of God and traveling around the world, carrying around pots and plates, since everyone was Greek and everyone was raving in idolatry? Rather, since they had Christ with them, they knew that an idol in the world is nothing, but everything is pure to the pure (Tit 1:15) and that he is sanctified through God's word and prayer (1 Tim 4:5); and as they went often into the house of a Greek, if they were able to convince the master of the house to believe in God, immediately they made the house a church. This happened in our very own city when the apostle Paul was in the house of Onesiphoros; the apostle didn't ask which vessels were clean and which were unclean. But this very house, as we said before, he made a church.

Jacobs argues that view that the house of Onesiphorus corresponds to a church is drawing from the Acts of Paul and Thecla, which I discuss below.

The (as far as I know, anonymous) Lives and Miracles of Saints Cosma and Damian (BHG 385-392) makes a reference to Onesiphorus being prayed for, but nothing particularly indicating that such prayers were for when he was in the next life:

Nor did he cease even afterward, visiting and taking care [of him], until he was about to, with joy, reach his own house (for he also was himself one of those who had fled for safety to the saints), so that at last the one who had been healed would pray for the man and say: “May the Lord grant him mercy, as to the house of Onesiphorus, because he often refreshed me and was not ashamed of my sickness. May the Lord grant him to find mercy from the Lord in that day.”

The spurious Index of Disciples attributed to Epiphanius lists: "56. Onesiphorus, of whom Paul himself also makes mention, became bishop of Coronea."  The spurious "Synopsis of Sacred Scripture" attributed to Athanasius mentions Onesiphorus in its summary, but does not suggest that he had shuffled off this mortal coil (or otherwise shed the skin of this mortal existence).  The spurious, "Of the Trinity" attributed to Didymus the Blind similarly just mentions the blessing of Onesiphorus, without any indication of his having left the church militant. 

Even the apocryphal and pseudepigraphic literature does not make any such suggestion.  The totally unreliable Acts of Paul and Thecla portray the house of Onesiphorus as including Onesiphorus, still living and actively participating.  The similarly unreliable Acts of Peter and Andrew portray a living Onesiphorus, though from the fragmentary nature of that work, it is less clear whether this is intended to refer to the Biblical Onesiphorus.  Pseudo-Hippolytus' work, "On the Apostles and Disciples," identifies lists "60. Onesiphorus, bishop of Corone," but nothing to clearly indicate either that this is the same Onesiphorus or that he was passed when Paul wrote of him.  However, in view of the Ps-Epiphanius list, it is natural to assume this is intended to refer to the same person.

The "Life of Onesiphorus and Porphyrius" is a martyrdom account of two Christians apparently killed under the persecution of Diocletian (284-305). While presumably named for the Biblical Onesiphorus, the account has no historical connection with Onesiphorus.

Interestingly, we know of the apocryphal character of the Acts of Paul and Thecla through the writings of Tertullian, who claims that the author (a Christian presbyter) confessed to writing the work and was deposed.  That means that, in some form, this story is at the latest from the 2nd century.  

I should point out that Roman Catholics do sometimes appeal to the Acts of Paul and Thecla for various points, such as to anachronistically suggest that the early church had the idea of Purgatory (see here, for example).  If they think it is reliable for that, they should also recognize that it is the earliest extra-Biblical tradition about Onesiphorus.  While fiction, it does not seem to reflect any contemporary belief that Onesiphorus had already died when Paul wrote Timothy.

In short, no.  There is no compelling reason to think that Onesiphorus must have been dead when Paul wrote 2 Timothy.  Thus, we should not assume that Paul's blessing of Onesiphorus and his house was posthumous.