Sure, I personally think you would be nuts not to worry about that, at least a little. Why you ask? Well… the stakes are so hi, yeah, that’s right, plain old fear… but that is ok. The other part is, God has given us so much, and we are wired for sin due to the fall etc.
I have to think of it like you would someone, a spouse your mother, someone you love dearly that you would never think of betraying. We owe that same deference to God. Even though we are forgiven, we… or at least I, still feel bad about it. It’s hard to work through or get your arms around. I guess that is the last part, faith, and trusting in God.