Don't you love Christian friends who honestly share their struggles and victories?
They help us know we're not alone and challenge us to be better. They're our "peer or friendship disciplers."
Peer mentoring is perhaps the most obvious and most underestimated form of discipleship. Just as "Bad company corrupts good character"(1 Corinthians 15:33), good company improves character.
It's good and right to be involved with non-Christians, but we must be careful to take our cues from Christian friends who are walking faithfully with Jesus.
We can do this deliberately by asking a friend to keep us accountable in a particular area and sharing honestly about our progress. Or we can do this by simply "listening" to the lives and words of Christian friends and asking God what He wants us to learn.
Sometimes these relationships happen naturally, sometimes not. If you don't have some important relationships that draw you closer to the Lord, I encourage you to pray about it.