A post like this can be confusing and divisive. Just like many others, i.e. OSAS or Not.
I am not a theologian or a master in Greek but I think I have a grasp of the Greek word for repent/repentance.
Here are my limited thoughts.
Most modern day dictionaries like Webster's will describe repentance along the lines of
'repenting for misdeeds or moral shortcomings which we do in order make our relationship right with God'
Koine Greek 'Metanoia (repent) meant something different. It meant changing one's mind or heart about something or someone,
However in the Old Latin and Latin Vulgate translated metanoia to paenitentia which came to mean pennance or acts of pennance to obtain grace.
What doesn't help and confuses the issue is what bible you may read
Matthew 4:17 NKJV
From that time Jesus began to preach and to say, “Repent, for the kingdom of heaven is at hand.”
Matthew 4:17 NLT
From then on Jesus began to preach, “Repent of your sins and turn to God, for the Kingdom of Heaven is near.”
Matthew 3:1-2 NKJV
In those days John the Baptist came preaching in the wilderness of Judea, and saying, “Repent, for the kingdom of heaven is at hand!”
Matthew 3:1-2
In those days John the Baptist came to the Judean wilderness and began preaching. His message was, “Repent of your sins and turn to God, for the Kingdom of Heaven is near.”
Can you see the difference?
Jesus did talk about sin which to me is the wrong things we do, like the adulteress woman BUT he did not condemn her.
John 8:10-11
Then Jesus stood up again and said to the woman, “Where are your accusers? Didn’t even one of them condemn you?”
“No, Lord,” she said.
And Jesus said, “Neither do I. Go and sin no more.”
Notice she said "No Lord"
Jesus said
John 16:6-9
But because I have said these things to you, sorrow has filled your heart. Nevertheless I tell you the truth. It is to your advantage that I go away; for if I do not go away, the Helper will not come to you; but if I depart, I will send Him to you. And when He has come, He will convict the world of sin, and of righteousness, and of judgment: of sin, because they do not believe in Me;
The Holy Spirit convicts us of sin, the sin of unbelief in Jesus.
When we repent of that we have changed our heart and mind about Jesus and have our placed our faith in him.
Now in doing so we have also changed our mind in terms of the things Jesus does not want us to do.
Going back to the adulteress woman, she called him Lord, then he says go sin no more, in other words he is saying
"Now that you acknowledge whom I am, I want you also to change your mind concerning how you live your life"
So to me when I came to Christ repented of my unbelief and at the same time I realised that Jesus wanted me to live differently.
To change my mind to not walk in the ways of the flesh and so on.
So to me I have already repented and when I do get it wrong I come before him and acknowledge that I have got it wrong.
I thank him that I am forgiven and ask him to help me.
As I said just my limited thoughts