The teachings of Jesus Christ say, “Ask, and it shall be given you; seek, and you shall find; knock, and it shall be opened to you” (Matthew 7:7). “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” (Revelation 3:20). So, when the Lord comes, how will He knock at the door? When the Lord knocks, what should we do to welcome Him? This is something everyone who believes in the Lord should ponder deeply.