Psalm of David, giving instruction, an instructive Psalm; so called by way of eminence, because it is calculated to give the highest instruction relative to the guilt of sin, and the blessedness of pardon and holiness or justification and sanctification. It is supposed to have been composed after David's transgression with Bath-sheba, and subsequently to his obtaining pardon.

Proverbs 23:17-18 “Let not your heart envy sinners, but continue in the fear of the Lord all the day. Surely there is a future, and your hope will not be cut off.

A descendant of Aaron, the first high priest of the Jews; so that “John the Baptist” was descended, on the father‘s and the mother‘s side, from priests. Our Saviour was not on either side. John would have been legally entitled to a place among the priests; our Saviour, being of the tribe of Judah, would not.

As we’ve seen, false teachers were threatening the new Colossian church. They probably had not yet gained many followers—at this point Paul was still “rejoicing to see [their] good discipline and the stability of [their] faith in Christ”
(Col. 2:5).

Romans 12:1
It starts with changing your thoughts.

For all have sinned
All have sinned
The first man defiled the nature, and ever since the nature defileth the man.
Adam was a parent, a public person, a parliament man, as it were; the whole country of mankind was in him, and fell with him.

Correct and sound doctrine is crucial to salvation and growth in spiritual maturity. It comes as no surprise that God warns us many times in Scripture to be aware of false teaching. Christians need to be able to recognize false teachers in order to know when they are being led down a path that God did not intend! The following Bible verses will help you determine whether someone is teaching false doctrine and how you should handle the deceptive teacher.
Ezekiel 13:9