I. The Father's Testimony to the Son
The Father testified to the son, calling him "My beloved son" on at least two occasions (Matthew 3:17; Matthew 17:5; Mark 1:11; Mark 9:7; Luke 3:22; Luke 9:35; and 2 Peter 1:17), namely at his baptism and at his transfiguration.
It is enough for us that the Father called Jesus his Son. That tells us who Jesus is. That's why Mark's gospel begins: "The beginning of the gospel of Jesus Christ, the son of God" (Mark 1:1).
II. Jesus Calls himself "First and Last" and "Almighty"
But did Jesus claim to be God? Jesus called himself the First and the Last, a title that belongs only to God, as it is recorded in Revelation:
"And when I saw him, I fell at his feet as dead. And he laid his right hand upon me, saying unto me, Fear not; I am the first and the last: I am he that liveth, and was dead; and, behold, I am alive for evermore, Amen; and have the keys of hell and of death." (Revelation 1:17-18).
We can see from Isaiah that this term is a term that refers specifically to YHWH, Jehovah, the Lord:
Isaiah 41:4 "Who hath wrought and done it, calling the generations from the beginning? I the Lord, the first, and with the last; I am he."
Isaiah 48:12 "Hearken unto me, O Jacob and Israel, my called; I am he; I am the first, I also am the last."
Likewise, Jesus calls himself "the Almighty" which is one of God's titles:
Revelation 1:8 "I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty."
The number of times this title is used of God are too numerous to mention, particularly in the book of Job, but beginning at least as early as the time of Abram:
And when Abram was ninety years old and nine, the LORD appeared to Abram, and said unto him, I am the Almighty God; walk before me, and be thou perfect.
Perhaps a good conclusion would be the words of Jesus in John 8:
Jesus answered, If I honour myself, my honour is nothing: it is my Father that honoureth me; of whom ye say, that he is your God: yet ye have not known him; but I know him: and if I should say, I know him not, I shall be a liar like unto you: but I know him, and keep his saying. Your father Abraham rejoiced to see my day: and he saw it, and was glad.There are reasons that Jesus did not constantly announce his divinity, both because he came in humility and because when he did announce his divinity (by calling God his Father, by calling himself "I am" ("And God said unto Moses, I AM THAT I AM: and he said, Thus shalt thou say unto the children of Israel, I AM hath sent me unto you." Exodus 3:14), and by saying that he was older than Abraham.
Then said the Jews unto him, Thou art not yet fifty years old, and hast thou seen Abraham?
Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am.
Then took they up stones to cast at him: but Jesus hid himself, and went out of the temple, going through the midst of them, and so passed by.
Moreover, there is an additional testimony to Jesus' divinity here. When the Jews picked up stones to stone him, Jesus hid himself and passed through their midst. Would God allow a blasphemer to escape judgment in this miraculous way? But if Jesus was not a blasphemer as the Jews accused him of being, then he was who he said he was: "I AM" who was before Abraham, the Son of God.
Thus we testify that Jesus is the Son of God. It is plainly stated numerous times in the gospels. The Father's testimony to the Son is enough for us, because the Father is God. Moreover, Jesus himself did claim divinity: he did so in a variety of ways, both during his time on earth and in his Revelation to John.
May the one Lord receive us to himself according to his mercy and his great love,