I can understand how after reading Matthew a person could jump to the conclusion that we are all called to instant conversion. Some might find comfort in their own instant conversion and lament the slowness of others. But Christ cautions to "judge not, lest that ye be judged..." . We don't know all the factors that inhibit a person from instant change. In my experience, I had to undergo a rigorous spiritual exercise in order to begin to change into the person that I believe God wants me to be. The good news is that God will meet me where I am, I have but to turn to him and surrender. He spies me in the distance and He runs to greet me.