From “How to become a Christian”: Chapter 14 – Step one in detail – repent
It is only after you become a Christian and begin the process of maturing, or sanctification, that you will realise just how sinful you really are. Whatever level of sinfulness you may think you have at the moment, you will have underestimated it. The longer you go on in the Christian life the more acutely aware you become of the true extent of your own sinfulness.
Awareness of sin is a little like consciousness of the bacteria on your hands. The average school boy would probably not give them a thought. He would not even be aware of bacteria at all, or care about them, even if told. However, his mother would be much more aware of bacteria on her hands and would give it some serious thought. So, her hands would be cleaner than her young son’s hands, and have fewer bacteria. Yet she would be more concerned about their cleanliness and would pay more attention when handling things than her son does.
If however we were then to look at a professional chef, his hands would be even cleaner than the mother’s hands, having fewer bacteria. Yet he would be even more concerned than her about the bacteria that remain, and would consider them an even bigger problem.
However, if we were then to look at a consultant surgeon, perhaps one who operates on tiny babies born prematurely, we may well find that before operating he washes his hands with the utmost carefulness for many minutes and thus has even fewer bacteria than a chef. Yet the few remaining germs on his hands would cause him even greater concern still. He would be acutely conscious of his hands and their cleanliness and the vital need to disinfect them. It would be at the forefront of his mind every day when at work.
That analogy works quite well to show how a Christian, as he matures in the Christian life, actually sins less in absolute terms. He gradually gains mastery over bad habits, thought patterns, and attitudes and begins to slowly weed them out, or reduce them, with God’s help. Yet, even though the sin in his life is getting less than it used to be in absolute terms, the fact that he is maturing means his ability to see his own sin increases.
Also his concern about his own sin increases. Therefore it is ironic that even though the level of sin gets less and less in absolute terms, a real Christian becomes more and more concerned about it in relative terms.
So, practically speaking, you have to begin by facing up squarely to the reality of your own sin and your need for repentance. If you do not get this right, then you will not get anything right. You may fail even to become a Christian. Or, if you do, then only a very weak one. If you can get this right however, and repent properly, then you will make excellent progress in the Christian life. You will rapidly mature in your first one to two years.
Repentance is a little bit like the elastic in a catapult. The more you pull back the elastic, i.e. the stronger the repentance, the farther you will be propelled forward in the early stages of the Christian life. The less however that you pull back the elastic in terms of your repentance, the more likely it is that you will make a feeble start. There will be no propulsion to get you started, or momentum to keep you going.