Leviticus 13:18-23: in context

This part of the law gives the priest careful instructions for examining a skin condition, a spot or swelling where a boil has healed. The priest looks closely: if the mark is deeper than the skin and the hair has turned white, it is declared unclean. But if it is uncertain, the priest isolates the person seven days and watches. The one test that decides the matter is whether it spreads. If it spreads, it is unclean; if it stays in its place and does not spread, it is only a scar, and the person is clean.

The decisive question in this careful examination is whether the mark spreads. A spot that stays contained is harmless, a mere scar; a spot that spreads is the dangerous thing, the disease taking hold. And so the priest watches, patiently, over days, to see which it will be. There is an analogy here that Scripture and the tradition have long drawn between such disease and sin, and the point about spreading is the sharpest part of it. Sin, like the disease the priest examined, is dangerous above all in its tendency to spread. A small compromise, left unchecked, spreads into larger ones; a private sin spreads into habit, and habit into character; a wrong tolerated in one corner of life creeps into others; and sin in one person can spread to a family, a community. What might have stayed a contained scar, dealt with and healed, becomes, if it spreads, something that takes over. The wisdom the priest's examination models is vigilance about what spreads: to watch our own hearts and lives for the small things that, left alone, will not stay small; to catch and deal with sin early, while it is still contained, before it spreads and takes hold. And there is patience in it too, the willingness to watch over time rather than judge in haste, to see whether a thing spreads before pronouncing on it. But the central lesson is the danger of what spreads. The sin we tolerate as small and contained rarely stays that way; like the spot the priest feared, its danger is in its spreading. Better to catch it early, examine it honestly, and deal with it while it is still a contained thing, before it spreads through the whole.

Is there some small compromise or sin I am tolerating as contained and harmless, and have I reckoned with its tendency to spread, as the priest watched to see whether the spot would spread, and will I catch and deal with it early and honestly, while it is still contained, before it spreads and takes hold of more than I meant to give it?