I’ve always dreamed of being able to ask a bible scholar certain questions. What a blessing your website is! Six members of my extended family, including myself, have heard knocking at the door when nobody is there. I can’t help but get excited when another family member hears the knocks. I truly feel that it is from the Lord, but not at all sure what it might mean. Have you had any other believers tell you of this happening to them, and do you have any insight on what could mean?
You may need an expert in the paranormal, not a bible teacher. I’ve never had a question like this from another believer, but in Rev. 3:20 Jesus said, “Here I am! I stand at the door and knock. If anyone hears my voice and opens the door, I will come in and eat with him, and he with me.” If you think this is what’s happening in your case, and the knocking on your door is Him calling you to faith, you should definitely respond.