Your choices regarding religious beliefs are entirely your business.  However, as I stated, I find it presumptuous for you to speak for "Christians."  I'm not a Christian or any other religion...I'm an agostic.  However, I do believe in the Golden Rule: Do unto others as you would have them do unto you."  It's a fitting representation of "secular humanism" as well as any religion.  

Let's apply that Golden Rule to a consideration of Mr. Trump's long personal, business and political history.  I seriously doubt you would contend Trump has ever shown any belief in such a rule......not hardly.  So, based on your approach, you (as a God-fearing Christian) should logically openly oppose Mr. Trump's presidency.  If you find this position problematic, you should, as you suggest "take it up with God."  Gary Crum