“Christ did sometimes go among the wicked; not that he approve of their sins, but as a physician goes among the diseased to heal them, so Christ intended to work a cure upon them (Mark 2:17). It was their conversion he aimed at.
“Though Jesus Christ did sometimes converse with sinners, yet he could receive no infection by them; his divine nature was a sufficient antidote against the contagion of sin. As the sun cannot be defiled with the thick vapours which are exhaled from the earth, and fly into the middle region, so the black vapours of sin could not defile the Sun of righteousness. Christ was of such spotless purity that he had no receptibility of evil. But the case is otherwise with us; we have a stock of corruption within. Therefore it is dangerous to incorporate with the wicked, lest we be defiled.
“Such as revere the divine majesty dare not go near the borders of sin. Those who went near the fiery furnace, though he did not go into it, were burned (Dan. 3:22)” (Thomas Watson, The Great Gain of Godliness, p.40).