At first it was pretty hard, I couldn't come up with decent rhymes and I'm a pretty smart guy. But as you start writing, try not to think in cement. I really dont know how to help if you need any, i just kept writing for a few days and it started coming.
There are some artists who just sit down and put out bars all day for a few days and its because you start thinking that way. Ill try to explain it later, pretty baked right now lol
Live a good, noble life and pay no attention as to whether gods exist. If they are just, they will judge you for your virtuous life, not your worship.