To accept people regardless of where they are at, and gently guide them in the right direction. That doesn't mean to accept their sin, and pretend that sin is okay.
It means, we teach that through Jesus Christ they don't have to live in sin. That they can change their ways through strength in Christ. We are to teach that Jesus came so we could all experience life changing forgiveness and newness.
So, yes we are called to be Christ-like. Not perfect but we are definately called to show the same grace, forgiveness and love. So that through our actions and lives people can see Jesus Christ and come to know him as Lord and Saviour.
I believe this is part of our witnessing, isn't it?