“A holy man will follow after purity of heart. He will dread all filthiness and uncleanness of spirit, and seek to avoid all things that might draw him into it. He knows his own heart is like tender, and will diligently keep clear of the sparks of temptation. Who shall dare to talk of strength when David can fall? There is many a hint to be gleaned from the ceremonial law. Under it the man who only touched a bone, or a dead body, or a grave, or a diseased person, became at once unclean in the sight of God. And these things were emblems and figures. Few Christians are ever too watchful and too particular about this point,” (J.C. Ryle, Holiness, 44-45).
Young Christians need to remember this when they watch implied fornication on TV, or when they listen to the lustful ravings of rappers. Constant wallowing in the mud of the world will have an effect. The pig doesn’t notice how foul they smell because they’ve gotten used to the stench.