He who warns people of sin is yet himself a servant of sin, looking upon the wrath of God. The servants of the Lord were sent forth to bid them to wedding feast.
The servants of the Lord are sent out to proclaim the Gospel of God's salvation to repent of their sin and turn back to Him.
2 Chronicles 7:14 If my people, which are called by my name, shall humble themselves, and pray, and seek my face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land.
How will they know what the wicked ways are if they are not taught to mortify them like what Paul listed in Colossians 3.
Jesus came to seek and save the lost and taught much regarding sin.
John 15:22 If I had not come and spoken unto them, they had not had sin: but now they have no cloak for their sin.
John 8:34 Jesus answered them, Verily, verily, I say unto you, Whosoever committeth sin is the servant of sin.
John 9:39 And Jesus said, For judgment I am come into this world, that they which see not might see; and that they which see might be made blind. 40 And
some of the Pharisees which were with him heard these words, and said unto him, Are we blind also? 41 Jesus said unto them, If ye were blind, ye should have no sin: but now ye say, We see; therefore your sin remaineth.
Hebrews 3:12 Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God. 13 But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin.
These are just a few examples where Jesus taught about sin.
