17. That no one can do any good that is good of himself is something the Lord teaches in John:

A man can receive nothing unless it has been given to him from heaven. (John 3:27)

Also in John:

He who abides in Me, and I in him, bears much fruit; for without Me you can do nothing. (John 15:5) “He who abides in Me, and I in him, bears much fruit” means that all good comes from the Lord. Fruit means goodness. “Without Me you can do nothing” means that no one can do good of himself.

People who believe in the Lord and do good from Him are called “sons of light” (John 12:36, Luke 16:8), “sons of the wedding” (Mark 2:19), “sons of the resurrection” (Luke 20:36), “sons of God” (John 1:12), and “born of God” (John 1:13). We are told that “they shall see God” (Matthew 5:8). That the Lord will make His abode with them (John 14:23). That they have faith in God (Mark 11:22). That their deeds are done from God (John 3:21).

These tenets are summed up in the following words:

As many as received (Jesus), to them He gave the power to become children of God, to those who believe in His name: who were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God. (John 1:12-13) To believe in the name of the Son of God is to believe the Word and live in accordance with it. The will of the flesh is the native character of a person’s will, which in itself is evil, and the will of man is the native character of his intellect, which in itself is falsity springing from evil. People born of these are those who will and act, and think and speak, in accord with their native self. People born of God are those who do these in obedience to the Lord.

In sum, good is not good that originates from man, but good is good that originates from the Lord.