Simply answered, for the sins of the world is why Jesus was crucified. This is what Jesus said to a Pharisee named Nicodemus:
John 3
[17] For God sent not his Son into the world to condemn the world; but that the world through him might be saved.
[18] He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
[19] And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil.
[20] For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved. (KJV)
So, what does God deem to be evil deeds that defile people? This is Jesus speaking again:
Mark 7
[20] And He [Jesus] said, "What comes out of a man, that defiles a man.
[21] For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders,
[22] thefts, covetousness, wickedness, deceit, lewdness, an evil eye, blasphemy, pride, foolishness.
[23] All these evil things come from within and defile a man." (NKJV)
John 3
[17] For God sent not his Son into the world to condemn the world; but that the world through him might be saved.
[18] He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
[19] And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil.
[20] For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved. (KJV)
So, what does God deem to be evil deeds that defile people? This is Jesus speaking again:
Mark 7
[20] And He [Jesus] said, "What comes out of a man, that defiles a man.
[21] For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders,
[22] thefts, covetousness, wickedness, deceit, lewdness, an evil eye, blasphemy, pride, foolishness.
[23] All these evil things come from within and defile a man." (NKJV)