I guess I just don't have any backbone. I promise God I'm not going to do something I know is wrong, but then I get with my friends and before I know it I'm doing it. I hate being such a weak person. Will I always be this way?
No, you won’t necessarily always be this way if you face your problems and sincerely seek God’s help to overcome them. The Bible says, “The Lord is my strength… my heart trusts in him, and he helps me” (Psalm 28:7).
Your real problem (at least in part) is that you desperately want other people to like you, and you’re afraid your friends won’t like you and will turn against you if you don’t do what they do. To refuse to go along with them would be the same thing as telling them they’re wrong and you’re right, and you fear they’d reject you as a result.
And you may be right; they might reject you. But if so, then they aren’t really your friends. True friends would care what happens to you, but they don’t. In other words, they’re tearing you down by pressuring you into doing what they do, and that isn’t true friendship. The Bible warns, “Do not be misled: ‘Bad company corrupts good character'” (1 Corinthians 15:33).
Begin by asking Jesus to come into your life, to forgive your sins and help you live the way you should. Then realize that you now belong to Him, and He is with you and will be your friend forever. Then ask Him to help you find new friends, friends who love God, and will encourage you and help you confront your temptations and grow strong in your faith.