Yes of course we should tell people about God but we should live life in such a way that we have a testimony. What I mean here is that some people tell everyone they are Christian but their actions,especially in their treatment towards others, say something different and by doing this other people are discouraged from coming to God. Don't be a "bible basher". We are all guilty of sin. It is only by the grace of God that we are saved and only by His son Jesus that we are forgiven. One should remember that when dealing with non believers :)