Now you're changing the subject to predestination and once saved, always saved.
Look at Hebrews 6:4-6
You can't fall away unless you're where you need to be to start with.
I think you need to look at Matthew 7.
You're not under the law, but that doesn't make you above the law. For the law to be in your heart, you need to see eye to eye with the law.
By the way, you do know that the ceremonial law ended at the cross, I hope.