That is the point of Jesus' parables of the wheat, the tares, and the dragnet.
There are times when it will be difficult to distinguish the manifestation of the kingdom of heaven, the Church and the lives of Christians, from the rest of the world. But the differences will be made known, and it is God who will do the final separation.
This is the last sermon of the series "Kingdom Parables". Take a listen, and go back and listen to the previous sermons as well. I hope you have been challenged, but I also hope you have grown in your understanding throughout this series as to what the kingdom of heaven is all about.