Repentance is a change of behavior based on a change of mind (Eze 18:30); it’s believing something different (Mk 1:15) and acting accordingly. (Ac 26:20)
As God commands us to repent (Ac 17:30) it sounds easy enough, but it isn’t actually something we can do on our own (Je 13:23); God must give us repentance (2Ti 2:25), turning us from darkness to light, delivering us from Satanic power and bringing us unto Himself. (Ac 26:18)
In order to repent we must first hear truth, then God must open our hearts to recognize it as truth (Ps 119:18) and help us believe and obey it. (Ps 119:35)
This process generally requires that we’ve already received some related truth that the new revelation connects to and extends; it’s a growth process. Without sufficient context to build on, we can’t always receive new truth. (Jn 16:12) God must help each one of us grow up in Him in a way that’s unique to our own particular frame and disposition. (1Th 2:7)
Since we can’t know the weaknesses of others, or even our own very well, it’s impossible for us to tell for sure what particular truths any given person is able to receive at any given time. (Ga 6:2) Like the layers of an onion, each of us has many issues for God to heal and repair (Is 28:10); only He knows what we can handle and when. (Ps 103:14)
We must bear patiently with each other (2Ti 2:24), and with ourselves, presenting that which is holy to those who are seeking (Mt 7:6), asking God to teach us all His way (Ep 4:21), not judging anyone, and leaving the results to Him.