Generally, doors in the Bible represent the initial desires for good and concepts of truth that introduce us to new levels of love and understanding, and even to the Lord Himself. Since a “house” represents a person’s desires, affections and passions, the door serves to introduce true ideas that can put those desires into action.

In John 10:7, the door signifies the Lord, who is good itself and truth itself. (Arcana Coelestia 2356[2])

In Revelation 3:8; 4:1, the door signifies admission to the arcana of heaven revealed. (Apocalypse Explained 260[2])

The meaning depends on context, of course. For example, references to doorposts and lintels are making a distinction between introductory goods and introductory truths. And, in Sodom, Lot's house had two doors -- an inner one and an outer one. When, in Genesis 19:6, Lot tried to convince the men of Sodom not to attack the angels visiting him, he went outside the inner door, but stayed inside the outer door. There, the outer door represents a desire for good that is resistant to the falsity represented by the men of Sodom; the inner door represents true ideas springing from that desire for good. Someone nurturing a desire for good could be admitted through the first door, but would have to learn the truth about how to express that desire before being admitted through the second.

(Odkazy: Genesis 19)

2357. 'And shut the door behind him' means to prevent them doing violence to good that flows from charity and denying the Lord's Divine Human and His Holy proceeding. This is clear from what has been stated so far. 'Shutting the door' is preventing their entrance, in this case into good meant by 'the house', and so reaching the Lord's Divine Human and His Holy [proceeding].

[2] These words embody even deeper arcana, the meaning and conception of which angels enter into when these words are read. The deeper arcana are these: People who lead lives of evil are not allowed to go beyond the point of mere knowledge of good and of the Lord. They are not allowed to go on to genuine acknowledgement and faith itself, the reason being that as long as they are governed by evil they cannot at the same time be governed by good. Nobody can serve two masters simultaneously. Once a person acknowledges and believes, he profanes that which is good and holy if he goes back to a life of evil. But a person who does not acknowledge and believe is not able to profane. The Lord's Providence therefore guards against anyone being allowed to go on to acknowledge and have faith itself in the heart, except insofar as he can then be maintained in that acknowledgement and faith. And He does so on account of the punishment that goes with profanation, which in hell is most severe.

[3] This is the reason why at the present day so few people are allowed to believe from the heart that the good which flows from love and charity is heaven itself within man, and that the whole of the Divine is within the Lord, for they lead lives of evil. This then is the more interior meaning of the statement 'to shut the door behind him', for 'the door' (ostium) was an inner door leading into the house itself where the angels were, that is, into good which has the Lord within it.