Some of those leaders would watch Jesus and try to catch Him doing something wrong (Mark 12:13-27) because Jesus told people that those leaders liked to lie and make other people do things they didn't want to do, and so a lot of these people gave up following those bad leaders and decided to follow Jesus instead (Matthew 23, Mark 7:1-7, Mark 10:1).

Then those leaders got really envious of Jesus when a bunch of people was following Jesus and not them anymore (Mark 15:8-10). So "they crucified Him" (Matt. 27:35).

But God made Him come back alive again (Matt. 28:7).

After that, some of Jesus' followers He called apostles started telling a lot of people about Jesus and how those leaders killed Him but God made Him come alive again, and since that happened they could have Jesus forgive them of their sins.

Those leaders who killed Jesus didn't like the apostles doing that very much so they put them in prison.

Then the high priest rose up, and all they that were with him, (which is the sect of the Sadducees,) and were filled with indignation, And laid their hands on the apostles, and put them in the common prison. But the angel of the Lord by night opened the prison doors, and brought them forth, and said, Go, stand and speak in the temple to the people all the words of this life (Acts 5:17-20).

But those apostles still told about Jesus.

And when they heard that, they entered into the temple early in the morning, and taught. But the high priest came, and they that were with him, and called the council together, and all the senate of the children of Israel, and sent to the prison to have them brought. But when the officers came, and found them not in the prison, they returned and told, Saying, The prison truly found we shut with all safety, and the keepers standing without before the doors: but when we had opened, we found no man within (Acts 5:21-23).

Well, the High Priest (he was especially responsible for killing Jesus) really did not like that at all, they're still talking about this Jesus (mostly because he knew he was guilty for Jesus' death and didn't want crowds of people turning on him and maybe beating him up or something).

Now when the high priest and the captain of the temple and the chief priests heard these things, they doubted of them whereunto this would grow. Then came one and told them, saying, Behold, the men whom ye put in prison are standing in the temple, and teaching the people (Acts 5:24-25).

So he made some soldiers go get those apostles and bring them back and make them talk in front of the council and the High Priest and then threatened them not to talk anymore about Jesus.

Then went the captain with the officers, and brought them without violence: for they feared the people, lest they should have been stoned. And when they had brought them, they set them before the council: and the high priest asked them, Saying, Did not we straitly command you that ye should not teach in this name? and, behold, ye have filled Jerusalem with your doctrine, and intend to bring this man's blood upon us (Acts 5:26-28).

But those apostles said they were still going to talk about Jesus anyway and weren't going to stop just because the leaders killed Jesus.

Then Peter and the other apostles answered and said, We ought to obey God rather than men. The God of our fathers raised up Jesus, whom ye slew and hanged on a tree. Him hath God exalted with his right hand to be a Prince and a Saviour, for to give repentance to Israel, and forgiveness of sins. And we are his witnesses of these things; and so is also the Holy Ghost, whom God hath given to them that obey him (Acts 5:29-32).

The Jewish leaders didn't like that at all.

When they heard that, they were cut to the heart, and took counsel to slay them (Acts 5:33).

One of them named Gamaliel said they should knock it off and leave the apostle men alone because who knows maybe they were doing what God wanted and then those leaders would really be in trouble fighting against God (as if they weren't already in trouble with God for killing His Son).

Then stood there up one in the council, a Pharisee, named Gamaliel, a doctor of the law, had in reputation among all the people, and commanded to put the apostles forth a little space; And said unto them, Ye men of Israel, take heed to yourselves what ye intend to do as touching these men. For before these days rose up Theudas, boasting himself to be somebody; to whom a number of men, about four hundred, joined themselves: who was slain; and all, as many as obeyed him, were scattered, and brought to nought. After this man rose up Judas of Galilee in the days of the taxing, and drew away much people after him: he also perished; and all, even as many as obeyed him, were dispersed. And now I say unto you, Refrain from these men, and let them alone: for if this counsel or this work be of men, it will come to nought: But if it be of God, ye cannot overthrow it; lest haply ye be found even to fight against God (Acts 5:34-39).

So those leaders agreed to leave the apostles alone (for now anyway) and after beating them up told them not to talk about Jesus any more.

And to him they agreed: and when they had called the apostles, and beaten them, they commanded that they should not speak in the name of Jesus, and let them go (Acts:40).

Those apostles were just happy and kept talking about Jesus anyway.

And they departed from the presence of the council, rejoicing that they were counted worthy to suffer shame for his name. And daily in the temple, and in every house, they ceased not to teach and preach Jesus Christ (Acts 5:41).

...

Then said Jesus to those Jews which believed on him, If ye continue in my word, then are ye my disciples indeed; Andye shall know the truth, and the truth shall make you free. (John 8:31-32).