Reference verse: "Therefore if anyone is in Christ, he is a new creature; the old things passed away; behold, new things come." 2 Corinthians 5:17 (NASB)
We as new Christians are a brand new tooth. We are white and clean, but we have rough places and weaker grooves in us, too. We are bombarded with harmful agents (darts and attacks from the enemy). Once in a while, we allow one of these to enter us through a weak spot.
It grows inside of us at first and it may not be visible to the naked eye, but it spreads and grows. Eventually the decay is so widespread that it breaks through to the surface where others can see it. The cavity and decay are very painful. We now have two choices.
Jesus can put a filling into the cavity. First He has to scrape out the rot and black, and that can be very painful, but He fills the cavity. The tooth is once again white and clean and as strong as ever. The enemy will attempt to bombard the former weak spot, but Jesus can protect that tooth with a fluoride treatment—His blood and His Word. That treatment seals over our weak spots. The harmful agents can come against the tooth, but the tooth is strong and protected. The tooth is strong enough to be attacked by the harmful agents and not allow the harmful agents to come inside to cause more damage.
We have another option, too. If we do not get the cavity fixed, the decay and rot continue to spread. It attacks the nerve that keeps the tooth alive (the spirit man). If we still do not get it fixed, the whole tooth will be taken over by the rot and decay, and the nerve can die. Once this happens, the tooth will eventually fall out completely.
