We've got to understand that these were bible-believing and bible based spiritual leaders that were shutting out the Kingdom in men's faces. These were hardcore believers of the true God that Jesus was accusing. And today, the same vicious thing is being repeated and propagated--in fact, it's been going on for centuries.
The church keeps to a routine church people have invented and called "sacred doctrines" to scare people from going against it and its system, and shun all moves of God towards a one genuine Jesus church, without denominations, spot, or wrinkle, or any other blemish. They won't enter into the Kingdom themselves (because they don't know how) and bars those who would, scaring them of turning into a cult.
They don't know how to enter the Kingdom, like Nicodemus didn't. He was Israel's teacher and yet he didn't get what being born again was. Many churches today do not know what genuine born again is and make it a formula for what they call "salvation" which really, to them, means joining their membership and being active in their church. They always relate salvation to joining their denominational church.
Most Churches are Nothing but Petty Pharisaical Kingdoms
As a result, many Christians worldwide do not know how to operate in the Kingdom and how to live the Kingdom life. They do not act like genuine Kingdom citizens. All they know are their denomination's policies, manuals, doctrines, and programs and activities. These things are not even what Jesus told Nicodemus about his "earthly teachings." These are worldly doctrines of man which do nothing but make worship "in vain," Jesus warned.
"These people honor me with their mouths (worship and pray to me in their churches) but their hearts are really far removed from me. Their teachings are nothing but rotten doctrines and traditions (rules) of men. As a result, they worship me in vain."
Men's theological teachings destroy people's spiritual lives--they result to hearts being far away from God even at the height of worship, even if they're really serious about their worship services.
Jesus stressed that it is men's teachings and traditions that ruin true worship to God, not worship styles or singing voice quality. It is knowledge derived from man's intellect, reasoning, and genius, no matter if it is full of bible verses. As long as your teachings are of human theology, your worship is trash in God's eyes. God wants nothing but spiritual wisdom and teachings given straight from the mouth of God through the power of the Holy Spirit--the power of the rhema Word in the bible and as spoken from the mouth of God. Something like what the apostles and the Acts church had--supernatural revelation from the Holy Spirit through spiritual gifts. If you don't have them and operate by them, you are a cult.
"This is what we teach you (wisdom straight from the Spirit), not in words used and taught by human wisdom but words the Holy Spirit Himself gives and teaches and uses, expressing and explaining spiritual truths using spiritual words."
It is ALL spiritual and supernatural.
Any human theology serves as a screen or filter that makes sure everything you get is mere human intellect and genius, nothing genuinely of God. It sounds heavenly and spiritual, studded with bible verses, but it's nothing but trash that makes your heart turn away from anything genuinely of God. Thus, most smart theologians do "not accept anything that genuinely comes from the Holy Spirit; they are mere foolishness to him. he cannot understand them because they are all spiritual and supernatural."
Hence, most church leaders cannot become as radical and extreme as Jesus was. They always fear radicalism and being extreme as "dangerous." No wonder the church has been weak and powerless for years. You see no more of the signs and wonders in Jesus' and the Acts church's days. You see nothing of the powerful and miraculous God in the Old Testament. All you see is man and his earthly doctrines and programs and his admonitions to stay "normal" and acceptable and safe.
Yes, they manage to produce converts with their evangelism, even mega churches of them, but as Jesus said, they only produce converts twice a child of hell as they are. These are church members who do not know how to find the true presence of God and really see where God is at work and what he is presently doing. They just go to church and do man's cute printed programs. And that to them is how you grow spiritually.
There's only one way to make sure you're not shutting out the Kingdom in men's faces--Jesus should be the one living your life. And if he does, you cannot but turn radical and extreme in the Word, in the Jesus LIFE, and the supernatural power of the Holy Spirit...all-out for the living God.