“You are the light of the world. A city set on a hill cannot be hidden. " Matthew 5:14

"No one lights a lamp and hides it in a jar or puts it under a bed. Instead he puts it on a stand, so that those who come in can see the light." Luke 8:16

Christians are called to be lights to the world, to contrast the darkness and sin. Unfortunately, many who profess to know God are living in darkness like the world, instead of lighting the path to heaven. How can they expect non-believers to desire a life of service to God, when, according to them, this also means continued service to the slave-driver of sin? Luke 16:13 says, "No servant can serve two masters. Either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve both God and Money." In the same way, one can't serve both God and sinful desires.

"6 If we say we have fellowship with him while we walk in darkness, we lie and do not practice the truth. 7 But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin." 1 John 1:6-7

How can we be cleansed from all sin yet still live in it? It doesn't make sense. If we are to be a light to the world, we can't be just like it. Those who sin are of the devil, the ruler of this world, as 1 John 3:8 boldly states.
"He who sins is of the devil, for the devil has sinned from the beginning. For this purpose the Son of God was manifested, that He might destroy the works of the devil."

Destroy the works of the devil. Not cover them up with a band-aid.