This might be a little bit of post so bear with me today haha. I may not word this perfectly but if there is any confusion, please say so and I will try my best to explain it. So everyone knows, this is not everything about or does it cover all reasons why God does what he does.
So many times, we have been told to go out into the world and give the gospel(good news) to everyone we come in contact with. This is very important since it is the only way that we can be saved and go to heaven since there is no other way to heaven except through Jesus(John 14:6). And honestly, if we have been saved ourselves, it can sometimes be hard for us to understand why anyone would reject the gospel of Jesus Christ.
Though there are several reasons why someone may not accept the gospel, we will talk about one that will offend some people. The answer is that the answer could be that God has hardened their heart for a time. Now don’t run away immediately because God has a reason for this. Even though we may not understand it at the current moment, the Bible does say that God has hardened peoples hearts before and even did it in the time of Jesus’s life on earth.
“Even though He had performed so many signs in their presence, they did not believe in Him. But this was to fulfill the word of Isaiah the prophet, who said: Lord, who has believed our message? And who has the arm of the Lord been revealed to? This is why they were unable to believe, because Isaiah also said: He has blinded their eyes and hardened their hearts, so that they would not see with their eyes or understand with their hearts, and be converted, and I would heal them. Isaiah said these things because he saw His glory and spoke about Him. Nevertheless, many did believe in Him even among the rulers, but because of the Pharisees they did not confess Him, so they would not be banned from the synagogue. For they loved praise from men more than praise from God.”
John 12:37-43
Hcsb Bible

Another very well known story of this is That of the Pharaoh in the book of Exodus in chapter 7:3-4. He says he does it here to some in the nation of Israel as well.
Now you may think that that it’s unfair but understand this that in every case of God hardening a persons heart, they themselves have been hardening their own hearts either by sinning without repentance or straight up rebelling and not wanting to believe God. In the case of Pharaoh, he rebelled against God in that he was ok with killing the unborn which is strictly against the word of God, also he refused to let the nation of Israel go after 400 years of slavery and murder. Then after plague after plague, he still didn’t want to and so God just gave him over to what he wanted to do with his sin. Even though God was on full display in his nation, Pharaoh still didn’t want to have anything to do with them. So he was already bent that way and was deep into evil.
The same can be said of the Israelites in Jesus’s time. They had known the law of Moses and still didn’t see Jesus come even though the Old Testament clearly describes him in prophecy (John 5:46). They had also seen and heard of Jesus’s miracle after miracles. For example, him turning water into wine, giving a blind man sight, curing the leper’s and raising a dead man back to life. So the Israelites that were hardened weren’t innocent but rather evil in their heart already.
So the question is why? Well if you know the story of the four Gospels, the nation of Israel had to reject Christ in order to fulfill prophecy and to push Jesus to die on the cross. Also pharaoh has to have his heart hardened so that God could show his glory to the world with the plagues and to bring the nation of Israel out of Egypt. So sometimes people’s hearts are harden to show Gods Glory.
One example is that a sinful man DECIDED to harden his heart and sin. He goes down this path away from God so that he then can be a great testimony of Gods love. This very same example is seen in the story of the Apostle Paul. He was a murderer of Christians and then God got the Glory of bringing him to himself and turning him into the biggest missionary to ever live.
Now in all of these situations, the person that was hardened, had a choice or free will if you want to use that terminology. But also in these same situations, God shows his sovereignty and power and strength in that he knew which people would be running from him and then used them to fulfill prophecy.
So from all of this, a hardened heart can be brought to Christ but we will never know until we bring them the Gospel. Now though that can be one of the reasons why they don’t accept the Gospel, it shouldn’t be a reason for us to not evangelize everyone we meet. It should give us even more reason in that our words can be a seed that could grow into them to bring them to Christ later.
So no matter what happens or what the reason is, always bring the truth and loving grace of the Gospel to others. No matter what the reason is that they may reject you. Now if anyone has any questions or comments or disagreements, just comment below or message me and I’ll respond when I can.
Thank you and I hope you have a great day and growing closer to God daily.