Both Jesus and John the Baptist began their ministry with a CALL TO REPENT message.
Repent means CHANGE, and is a call to change. The Greek word underlying repent means to change or move the mind and thinking. Jesus preached, repent and believe the Gospel (Gospel means good news). Jesus came to set the captives free and spoke of truth setting free.
Real and true repentance is leaving behind erring concepts and manners and finding and grasping God's truth. Such repentance has promise of good for the life that now is and of that which is to come! Real repentance involves God moving and teaching us directly or indirectly through others! Earnestly pray that God would teach and move us! God moves and changes desires and attitudes, not only concepts, in the repentance change.
Real and true repentance yields to Christ's teaching, who is the way the truth and the life! It yields to the Spirit of Truth, which Jesus said would lead us into all truth. Often it is religious people who need to repent from religious errors, which may be very ancient or deeply rooted.
Repentance does not resist the truth, nor close its eyes to it, but with an open heart seeks truth as if it were GOLD. On the other hand non repentant ones often refuse to think and believe facts, and rather seek to convince themselves that truth is whatever they were taught or want it to be. Such ones often blindly and firmly hold to past erroneous teachings and resent those who expose cracks and discrepancies in their imagined truths, and might almost become angry with them.
Oh may God help us to honestly and open heartedly seek for truth, while having a readiness to repent and change our minds and manners. And may such a sincere search unite rather than divide those in the search!
Many Christian denominations strongly accuse each other of error, while they themselves have much or no less error. In my personal research for truth I quite often had to change my mind and views. Therewith I also experienced much rejection by religions which largely make it against their religion to question anything about their religion. God in His mercy gave me many signs and wonders to encourage and teach me in my search. The below fence page from another of my documents nicely relates to these issues.