Gettysburg Address ... easy question? maybe

[L Verge]

Do you think that Lincoln's idea of God was based more on the God of the Old Testament? Could that be a reason for his acceptance (that's not exactly the word I want to use, but...) of Jewish tenets and advice from Jewish men during his administration?

Also, if he did not have some appreciation for the Bible, how could he place his hand on it during both inaugurations? And, refresh my memory - did the inaugural oath include the word "God" in 1861 and 1865?

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I semi-answered my question with this online fact: " There is no law that requires Presidents to use a Bible or to add the words 'So help me God' at the end of the oath. Historian John R. Alden maintains that Washington himself added the phrase to the end after administration of his first oath."

Now, since it is not required, have there been any presidents who chose not to invoke the help of God in their oaths over the centuries?

BTW: I learned that Madison and George Mason are credited with writing the bulk of the oath - only two phrases were changed by the committee. Ironically, in the case of Lincoln, he was uttering an oath created by two Southerners...