I think it’s immoral because the belief asserts that if you don’t follow him, you will burn for all eternity. Christianity is merely tyrannic bogus, a scare tactic that leaves its followers praying for something better, and even with other religions like Judaism, you seek to make amends with God in order be acknowledged.
God knows love fully, and you don’t need to make deals with “him.” It’s similar to being with your friends and family members. You don’t need to sweet talk around them, as you are accepted no matter what.