Rev. 3:20 Behold, I stand at the door and knock. If anyone hears My voice and opens the door, I will come in to him and dine with him, and he with Me.
Jesus is not knocking on the door of your heart. He is a sovereign God who chooses those who He elects. He is not an irresponsible God who is weak, hoping that men will come unto Him. He is not knocking like a beggar, sad and wanting. Christ does not appeal to His creature and change in light of their fickleness. Christ is not in the heavenlies wringing his hands in angst, sweating at the brow, wondering the outcome. He is immutable and powerful; all things through Him are made straight.
Rev. 3:22 “He who has an ear, let him hear what the Spirit says to the churches.”
Possibly, Heaven would be empty if left in the hands of an unfaithful people. Jesus rebukes those churches which are greatly failing. He knocks on the door of those churches, rightly warning them to repent and do those things which He has taught. Repent or be spit out!