President Trump used a speech at the National Prayer Breakfast to repeat his pledge to abolish the Johnson Amendment that prevents religious organisations engaging in political campaigning.
"I will get rid of and totally destroy the Johnson Amendment and allow our representatives of faith to speak freely and without fear of retribution," he told hundreds of religious leaders.
Trump also took aim at Arnold Schwarzenegger, who took his place as host of The Apprentice, saying ratings had gone down and that he had been a "total disaster".
He told the audience: "What I hear most often as I travel the country are five words that never, ever fail to touch my heart - that's 'I am praying for you.'"
He paid tribute to the military, saying: "Our soldiers understand that what matters is not party or ideology or creed, but the bonds of loyalty that link us all together as one. America is a nation of believers."
He spoke of his own faith, saying: "I was blessed to be raised in a churched home. My mother and father taught me that to whom much is given, much is expected. I was sworn in on the very Bible from which my mother would teach us as young children, and that faith lives on in my heart every single day.
"The people in this room come from many, many backgrounds. You represent so many religions and so many views. But we are all united by our faith, in our creator and our firm knowledge that we are all equal in His eyes. We are not just flesh and bone and blood, we are human beings with souls. Our republic was formed on the basis that freedom is not a gift from government, but that freedom is a gift from God."
Trump also spoke of threats to freedom of religion, saying: "Freedom of religion is a sacred right, but it is also a right under threat all around us, and the world is under serious, serious threat in so many different ways. And I've never seen it so much and so openly as since I took the position of president. The world is in trouble, but we're going to straighten it out. OK? That's what I do. I fix things. We're going to straighten it out."
He cast his immigration ban as a defence of religious freedom, pledging that that America would be a safe and free country.
Trump said: "As long as we have God, we are never, ever alone. Whether it's the soldier on the night watch, or the single parent on the night shift, God will always give us solace and strength, and comfort. We need to carry on and to keep carrying on."