Before Jesus started his earthly ministry, John the baptizer prepared the way for him.
The Jews had to repent of their sins before Jesus would come and forgive them.
Luke 1:76 And you, child, will be called a prophet of the Most High; for you will go on before the Lord to prepare His ways, 77to give to His people knowledge of salvation through the forgiveness of their sins, 78because of the tender mercy of our God, by which the Dawn will visit us from on high,
See, Jesus was coming to preach a New Covenant, and then he shed his blood on the cross for the New Covenant.
The Old Covenant was not based on faith, it was based on the ceremonial works.
Some Jews had faith in God before Jesus came, and some Jews did not.
The Jews who did not have faith were cut off and hardened while Jesus was on earth.
The Jews who had faith in God before Jesus came to earth, they recognized what Jesus was saying was from God. They were God's and He gave them to Jesus, they now had to go through Jesus to remain God's. Jesus said he would not lose one that God gave him.
Jesus says that when he is crucified, he will draw ALL to him.
That means even the Jews who were cut off could be grafted back in, if they have faith in Jesus' blood cleaning them of the sins they repent of.
Paul calls it Jews first then Gentiles.
Romans 1:16 For I am not ashamed of the gospel, because it is the power of God that brings salvation to everyone who believes: first to the Jew, then to the Gentile.
Romans 2:9
There will be trouble and distress for every human being who does evil: first for the Jew, then for the Gentile;
Acts 3:26
When God raised up His servant, He sent Him first to you to bless you by turning each of you from your wicked ways."
John 12:32 And I, when I am lifted up from the earth, will draw all people to myself."
Romans 11:23 And if they do not persist in unbelief, they will be grafted in, for God is able to graft them in again.
I have many more scriptures and things to tell you to help you understand.
Jesus was God and could forgive anyone he wanted to forgive, but, he still had to shed his blood for the forgiveness of sins, to wash us in his blood. That is where faith comes in. One must believe that Jesus' blood washes away their sins and that he himself will then live inside you.
Jesus taught the guidelines for the New Covenant, and then he shed his blood on the cross for the New Covenant. He is the Sacrificial Lamb once and for all.
Hebrews 9:22 In fact, the law requires that nearly everything be cleansed with blood, and without the shedding of blood there is no forgiveness.
Leviticus 17:11
'For the life of the flesh is in the blood, and I have given it to you on the altar to make atonement for your souls; for it is the blood by reason of the life that makes atonement.'
See even if Jesus forgave someone before he shed his blood, they still did not receive his Spirit. He had to shed his blood and one must have faith that his blood washes away their sins before Jesus will make his home inside your heart.