Commercial kitchen owners and operators know about grease traps. Grease traps are essential to drainage systems from commercial kitchens, for they “catch” and “collect” most of the greases and/or solids that 
come from the kitchens before they reach the sewer system. But, here’s the thing: these grease traps must be cleaned out on a regular basis, otherwise they will “collect” so much grease that it will block the drain lines from the kitchen and cause messy backups. “Collecting” the grease is important, but “cleaning” it is even more vital in the long run.
Somewhere in here is a spiritual lesson (or two). In our spiritual lives, our souls have something like a “grease trap.” It “catches” and “collects” all of the sins that we commit. Imagine how clogged it can become over time. On a regular basis, we need to have that trap “cleaned out,” so that we can avoid messy backups. When one is baptized into Christ, the blood of Jesus completely purges all sin from our “sin trap.” Then, as Christians, as we continue to “walk in the light” of purity and fellowship with God, He keeps on cleansing our “sin trap” (1 John 1:7)!