If anyone hears the voice of Jesus and opens their door, He will have fellowship with them  -  Revelation 3:20

Behold, I stand at the door, and knock: if any man hear my voice, and open the door, I will come in to him, and will sup with him, and he with me.

In the time in which we live, Jesus is on the outside knocking to be let in. It is not due to Him being unable to get in or to open the door Himself but it is because people refuse to open their hearts and lives to let Him in. Jesus still desires to fellowship with individuals but the individual must desire to fellowship with Him, to the point of opening the door.