It seems the quote "The Lord giveth and the Lord taketh away" belongs in the same category as "Elementary, my dear Watson" and "Play it again, Sam".
What Job actually said, according to the King James Bible, was "the LORD gave, and the LORD hath taken away".
(Immediately before that, he said, "Naked came I out of my mother's womb, and naked shall I return thither". I wonder if his mother was aware of his plans?)
However, there are numerous other places in that esteemed translation of the Bible where giveth appears. It was also used by Shakespeare, though only once. So the word will be accepted.
And, to be consistent, we should also allow taketh - and the second person singular forms givest and takest. All of these are also found in the Bible and Shakespeare, among other works of literature.