The human nature Christ brought to earth is God-centered. So, God himself as Man accepts all the consequences of sin, and on the cross reveals in one perfect classic occasion God's own condemnation of sin and his own love of sinners. Nobody can look at a crucifix and think God condones sin. There is the punishment of human nature. Nobody can look at it and say God does not love sinners.
All sin really is unbelief.
The sins which are hardest to combat are solitary sins, such as taking drugs or committing impure acts, done while no one's looking on. When people really believe in Christ, who is always present, they are saved because of that presence. It is the work of prayer to pierce these disguises, and to attain that pure intention from which self-love is always seeking to deflect us. There are many voices that call us in life, especially television and popular culture. Prayer enables us to reject the lure of the lower impulses to accept the call of the higher.