I heard something interesting in KK's post and I thought it was time to do my own rambling.
His post says that we shouldn't "push" people into Christianity, but rather "pull" them into it. I whole-heartedly agree, and I feel like I have some interesting thoughts to add. Whenever you push something, you're stepping outside of the bounds of where it's going, and using force from the other direction to get the task accomplished. With witnessing, we don't want to use the world's tactics to try to reach goals set by God.
Jesus never forced a person into the faith, never elbowed them or shoved them so that they would seek Him. I always imagine Him as being a kind, loving person, however a man who was also so filled with things of God that the people around Him could see it. They knew that He knew something, but He never had to convince them of it. In this way He gained a lot of respect from some people, but others grew to hate Him.
I think a good Christian witness is the kind where you feel very guilty and sore after meeting with them, but they never did anything to cause it. I know a friend of mine who is very serious about Christianity and so driven to God, that when I interacted with him, I felt guilty myself about my own walk; but he never did or said anything that was intentionally aimed at making me feel that way. He simply lived his life and it was more effective than any sort of verbal exhortation I'd received.
I think that there is room for both exhortation from the pulpit and some healthy exhortation outside of a Sunday morning (or whenever you hear preaching), but I don't think that it lends towards helping a brother as much as living in a Godly way yourself. When you walk into a church, you have given the preacher permission to exhort you. However, in your day-to-day life, any random one of your friends may not have the kind of respect in your eyes that warrants verbal exhortation. I know that some of my friends have tried to talk to me about how to improve on certain aspects of my life, but a lot of them don't have my respect in those areas, so I can't really listen to them. It's not that I need someone who's never failed to tell me I'm wrong (I have Jesus for that), I just need someone who is living that way right now.
Anyway, this is also totally unstructured mess of thoughts, but hopefully it will spur more thoughts onward.