On Friday, January 20th, religion popped up on the front pages of most news websites and TV channels in the country, soon followed by virtually every daily piece of print journalism. Most of these stories on Trump’s inauguration came with large pictures depicting his swearing-in, but each of them also included the Bibles on which he laid his hand. Melania held two Bibles, one that Lincoln had used for his own inauguration and one that Trump’s mother had given him when he graduated from Presbyterian Sunday School in 1955.
The first Bible from Lincoln seems a strange choice, given the disparity between Lincoln’s legacy of uniting the country and Trump’s divisive political style. The choice appears even more odd given that using the Bible is far from Presidential tradition; Obama is the only previous president to have sworn in on it. However, the chairman of the Inauguration Committee explained that the Bible harkened back to moment when President Lincoln “appealed to the ‘better angels’ of our nature,” suggesting vaguely that Trump wanted to echo Lincoln’s request.
The other Bible harkens back to Trump’s childhood. After graduating from his Confirmation class in 1959 in Jamaica, New York, Trump’s mother gifted him with his own Bible. On the campaign trail, he referenced that Bible several times and even used it in a video to his evangelical supporters, touting it as a proof of his longstanding faith. In a way, then, this Bible acknowledges the evangelical electorate that is largely responsible for his election.

https://www.washingtonpost.com/news/morning-mix/wp/2017/01/18/the-symbolism-of-trumps-two-inaugural-bible-choices-from-lincoln-to-his-mother/?utm_term=.0b7f70d3795f