Don't do it just because you are young.

It means: you can't think that just because good deeds are small, you don't have to do them. You can't think that you can do evil often just because it is small.

I ching said: the accumulation of good is not enough to become famous, and the accumulation of evil is not enough to destroy the body. The villain gives away small kindness as useless, and gives away small evil as harmless. Therefore, it is difficult to hide evil and there is no solution to the crime.

It means: if you don't accumulate good deeds, you won't be famous in the world, and if you don't accumulate evil deeds, you won't be able to destroy yourself. When a villain does something, he thinks that doing small good deeds will not get any benefits, so he simply doesn't do it, and he thinks that doing small wrong things won't hurt the overall situation, so he doesn't change it. So over time, evil will flood the world, so that it can't be hidden and saved.