-A person can believe in Jesus for God's free gift of Eternal Life without repenting of sin/sins. Repenting has noting to do with believing in Jesus
So a non Christian can fully accept who Jesus was, that he came to earth to die for our sins and reconcile us to God, that he told people to repent, (Mark 1:15, Luke 13:5) and that he said his blood was for the forgiveness of sins - but they don't need to repent of those sins?
You believe people went to the moon, did you have to repent to believe this.
Did I have to repent of what?
No, I accepted that what I saw on television was a fact. There was nothing to repent, or change my mind, about - men couldn't get to, and walk on, the moon, and then they could.
Believing is simply being convinced something is true.
People can be totally certain that Jesus existed, lived, taught and died, without really and fully accepting the fact that God loves them, personally.
Christians can be intellectually convinced that the Holy Spirit exists and yet have not asked to be filled with/baptized in the Spirit so that he totally transforms their lives. The book, "9.00 in the morning" describes this; I think Colin Urquhart wrote about it too.
In Acts 19 there were Christians who believed in Jesus but "had not even heard" that there was a Holy Spirit.
The NT often has the word "know"; John said he was writing so that people would know.
The Hebrew word for "know" meant, "knowing in such a way that it transforms your life". It wasn't just intellectually accepting, it was doing something about it. I have recently read a book in which the author says the same thing; if the information you have accepted does not change your life, if you don't put it into practice - you don't know it. How many people say the Lord's Prayer but do not know God as their loving, perfect heavenly Father?
So how can a non Christian know that Jesus died for their sins and that if they accept that they are reconciled to God - yet not have to repent of their sins?