The will of the father is to believe on the Son, according to John 6:40. To "believe on" the Son means to trust him to save you. If you are trusting anything else but Jesus, you don't truly believe on him.
“John the Baptist preached repentance.”
Acts 19:4 Then said Paul, John verily baptized with the baptism of repentance, saying unto the people, that they should believe on him which should come after him, that is, on Christ Jesus.
Did Jesus say the publicans and harlots quit being publicans and harlots? No! He said that they believed him. Once again demonstrating that repentance had to do with what they were believing, not what they were doing.
Notice that Jesus said the Pharisees did not repent afterward that they might believe him. In other words, the repentance they needed to do was to believe what was being preached. When you get the right definition of "repentance", this makes perfect sense.
"Repentance just means you have to be willing to stop sinning."
"'Repent of your sins' just means realize you are a sinner"
I can see where someone may say that changing your mind about your sins means just realizing that they are a sinner. But the Bible never uses the phrase "repent of your sins." The problem is that it is so easy to misunderstand this to mean you need to stop sinning, thus making this phrase very deceptive.
Why would you insist on using this phrase, when it is not in the Bible? Why not use a more Biblical phrase, like “repent of your dead works” (Heb. 6:1) if you feel you have to say “repent” somewhere? But in reality, this is all summed up in believing on the Lord Jesus Christ, which is why that is what the Apostles and Jesus emphasized. When asked "what must I do to be saved" they answered "Believe on the Lord Jesus Christ, and thou shalt be saved." When the Ethiopian Eunuch wanted to get baptized, Phillip asked if he believed with all of his heart. That's what the Bible emphasizes about salvation, not repentance.
"A person that is truly saved will repent of their sins"
"Repentance from sins isn't works because God gives you the repentance" (2 Tim. 2:25)
Let's take a look at this verse:
Salvation is by believing on Jesus Christ alone for salvation. Therefore, you must repent of anything else you are trusting in to save you and place all of your faith in Christ.