The Bible says in Luke 11:52 KJV
Woe unto you, lawyers! for ye have taken away the key of knowledge: ye entered not in yourselves, and them that were entering in ye hindered.
Who are the lawyers? Any teacher or preacher of the Word of God is a lawyer. It is impossible to teach or preach the Word without practicing law. Unfortunately, Christianity is rampant with malpractice.
How do they prevent others from entering into the Kingdom of Heaven: misinformation and incorrect doctrine. They bring people to the door. They teach a “Prayer of Salvation” and do not usher the people through the door.
Baptism is crucial to salvation. Mark 16:16. It is being born again. Only after baptism do you enter into the Kingdom of God.
Be careful to not place anyone between yourself and the door of Heaven. Study on your own to show yourself approved. 2 Timothy 2:15. Remember James 1:5 KJV,
If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him.