I'm a terrible christian
What makes you a terrible Christian?
I have a hard time following the rules of the Bible.
You can improve yourself in this area. You recognized that work needs to be done, now you can start doing it.
I know, but I'm going to continue to be a terrible christian.
If you feel down about yourself being a terrible Christian, then you should work to change that. Go to church more or ask your pastor for tips on how to better follow the practices.