I don't think he's actually quoting from the Bible there. The novel was published in 1929, by the way, and in that time, the King James Version was "the" Bible. Well, to be more accurate: the King James Version was "the Bible" to Protestants, while English-speaking Catholics used the Douay-Rheims (but placed much less stress on individuals reading the Bible for themselves--Protestantism and "the priesthood of all believers" led to the need to make the Bible available in native tongues, and, directly, to Gutenberg and the development of movable type and printing in the European world). Backing up: there's almost no chance that he would have been quoting from any translation but the King James. Even the Revised Standard Version was not published until, let me see: 1946. NIV not until 1973. There is a possibility that he was referring to the Book of Common Prayer, but it's unlikely, and the wording isn't close enough. However, one of the prayers contains the lines: "We have offended against thy holy laws. We have left undone those things which we ought to have done; And we have done those things which we ought not to have done; And there is no health in us."

Why do you think he's quoting Roman 7:15, by the way? (It is, by the way, completely possible that it's a very loose paraphrase... or that Hemingway may not have known it was from the Bible, it might have just been a phrase he overheard).