The most famous Granville-Sharp Rule, one of six, states:
When the copulative kai connects two nouns of the same case, if the article ho or any of its cases precedes the first of the said nouns or participles, and is not repeated before the second noun or participle, the latter always relates to the same person that is expressed or described by the first noun or participle; i.e. it denotes a farther description of the first-named person.
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Some have suggested that the discovery of this rule is significant in two ways: (1) to demonstrate the divinity of Christ, since some of the Granville-Sharp uses are places in which Jesus is referred to as God, and (2) to demonstrate errors in the King James Version translation.
I have no objection to the first usage, and I only want to temper the second use.
My tempering of the second use is based on the rhetorical device known as hendiadys.
Webster's 1913 explains it thus:
Hen`di´a`dys
n. 1. (Gram.) A figure in which the idea is expressed by two nouns connected by and, instead of by a noun and limiting adjective; as, we drink from cups and gold, for golden cups.
The American Heritage Dictionary has a very similar definition:
hen·di·a·dys (hĕn-dī´ə-dĭs)
n.
A figure of speech in which two words connected by a conjunction are used to express a single notion that would normally be expressed by an adjective and a substantive, such as grace and favor instead of gracious favor.
There are places in the Bible where we see hendiadys used in the source language, and literally provided in the English translation. For example
Gen 3:16 Unto the woman he said, I will greatly multiply thy sorrow and thy conception; in sorrow thou shalt bring forth children; and thy desire shall be to thy husband, and he shall rule over thee.
The sense of the text is not that sorrow and conception are distinct and separately multiplied, but that God will multiply the woman's birth pangs.
What about the New Testament? This is where the matter becomes more hotly debated. Partly it is debated because of the absence of classical Greek references to the use of hendiadys: the term itself was apparently coined around A.D. 400. On the other hand, the New Testament writers were influenced by the writings of the Old Testament in which it is hard to argue that hendiadys was not employed. Accordingly, it is reasonable to suppose that least some passages of the New Testament employ such usage.
My speculation is that the Granville-Sharp Rule is a reflection of an understanding of the use of hendiadys in Greek. In other words, the reason for the lack of duplication of the article is that the author was employing the rhetorical device of hendiadys.
If that's the case, then the English literal translation of "A and B" provides a rhetorically equivalent translation to the source Greek text, just as it does to the source Hebrew text. The challenge is that it can be exceedingly hard to distinguish hendiadys in English. Mark Forsyth characterizes hendiadys as "the most elusive and tricky of all rhetorical tricks. Mostly because you can never be sure whether it's happened." ("Elements of Eloquence," p. 74) Forsyth is overstating his point, for rhetorical effect no doubt, but the point remains. In English, it can be very hard to distinguish hendiadys.
Thus, even if "our God and Saviour" is hendiadys and means "our Divine Saviour" or "our Saving God" or the like, it is hard to grasp that sense in English merely from a literal re-creation of the Greek hendiadys (if that is what it is). Accordingly, there might be reason to provide the reader with a less literal translation and to provide the literal translation and a brief explanation in the margin.