Matthew 23:13 “But woe to you, scribes and Pharisees, hypocrites! For you shut the kingdom of heaven in people’s faces. For you neither enter yourselves nor allow those who would enter to go in. Woe to you, scribes and Pharisees, hypocrites! For you travel across sea and land to make a single proselyte, and when he becomes a proselyte, you make him twice as much a child of hell as yourselves.
Luke 11:52 Woe to you lawyers! For you have taken away the key of knowledge. You did not enter yourselves, and you hindered those who were entering.”
Isaiah 56:10-11 His watchmen are blind; they are all without knowledge; they are all silent dogs; they cannot bark, dreaming, lying down, loving to slumber. The dogs have a mighty appetite; they never have enough. But they are shepherds who have no understanding; they have all turned to their own way, each to his own gain, one and all.
John 9:39-41 Jesus said, “For judgment I came into this world, that those who do not see may see, and those who see may become blind.” Some of the Pharisees near him heard these things, and said to him, “Are we also blind?” Jesus said to them, “If you were blind, you would have no guilt; but now that you say, ‘We see,’ your guilt remains.
The religious leaders kept people from the kingdom of heaven by making human traditions and human religious rules more important than God’s Word. This was clearly seen in the way that they opposed and rejected Jesus; if they had opened the kingdom of heaven to men, they would have welcomed and received Jesus as the Messiah and Son of God. It is bad for someone not to enter into heaven themselves, but it is far worse to prevent another person from entering in.
Their zeal in evangelism did not prove they were right with God. These religious leaders went to great lengths to win others, but they brought people to darkness, not light. They may have a zeal for God but not according to knowledge. Having a zeal for a false message does not make the message true. Leading a person down a path to hell with a false message has consequences for both the message giver and hearer. The blind proclaiming they can see and are able to lead other blind people to light does not make it true. Zeal, no matter how great it is, plus false doctrine, no matter how great the persuasion in their message, will never give rest for the blind soul seeking lasting light with purpose, hope, rest, joy, peace, and courage.
Anything apart from the gospel of Jesus Christ, or apart from bringing Him all the glory and honor, or adding to, or taking away from His complete atonement for sin, or by some means of self-reliance, will always lead to blindness to things of God and lead a person to become a tool for satan and his lies.
We do well to desire God to expose us to whatever is in our heart, mind, and soul that does not honor and glorify Jesus Christ and also be ever desiring to hear those quiet whispers for leading.