The businessman, who wants to run for US President in 2016, said court rulings going against Christians was "really outrageous".
"A week doesn't go by where there's not some negative ruling on something having to do with Christianity," he told a radio show.
"I'll be fighting on the other side, much stronger than anybody else that you have up there fighting, because I think it's really outrageous."
Mr Trump, raised as a Presbyterian, added that "deep down, maybe" the Gospels would influence his political choices.
He said he was angry that the word Christmas was being "taken out" of everyday use: "I see these stores like Macy's and so many others, they're afraid to use the word 'Christmas' now.
"Maybe they can't use it, legally. What's going on is outrageous, and I would try and, not only try, I will do things about it.
"You're going to have to go through court systems. That's the problem. You have to go through actually courts now to use names that you should be able to use automatically.
"You can't do anything having to do with really deep-seated, incredible beliefs that really, to a large extent, made our country great.
"You know, these, the beliefs in the Bible had a lot to do with our country."
But the presidential hopeful has faced accusations of 'faking' his faith to win votes.
Asked by Bloomberg's 'With All Due Respect' what his favourite Bible verse was, he refused to answer, despite having previously described the book as his "favourite".
"I wouldn't want to get into it because to me that's very personal. You know, when I talk about the Bible, it's very personal, so I don't want to get into verses," he said.
"The Bible means a lot to me, but I don't want to get into specifics."
Asked whether he preferred the Old Testament or the New Testament he said: "Probably equal".
