The man who did not wear the proper wedding garment was unprepared for the banquet. In that culture the proper wedding garment was just clean clothes. [1] He was there, whether evil or good ( Matthew 22:10), because he had accepted the king"s gracious invitation. However he was subject to the king"s scrutiny. The king addressed his guest as a friend. He asked how he had obtained admission without the proper (clean) garment. The man was speechless due to embarrassment. Then the king gave orders to his servants (Gr. diakonois) to bind the man hand and foot like a prisoner and to cast him out of the banquet hall. They would throw him into the "outer darkness" (NASB) or "outside, into the darkness" (NIV). The place where he would go would be a place of weeping and gnashing of teeth. [source][source][source]
It is probably significant that Jesus referred to the king"s slaves (Gr. douloi, Matthew 22:3-4; Matthew 22:6; Matthew 22:8; Matthew 22:10) as heralding the kingdom, but He said the king"s servants (Gr. diakonoi, Matthew 22:13) evicted the unworthy guest. Evidently the slaves refer to the prophets and the servants to the angels. [source][source][source]
These verses have spawned several different interpretations. One view is that the man who tries to participate in the banquet but gets evicted represents those whom God will exclude in the judgment that will take place before the kingdom begins. [2] This view takes the man evicted as representing a Jew who hopes to gain entrance to the kingdom because he is a Jew. Since he does not have the proper clothing, the robe of righteousness, he cannot enter the kingdom. The lesson Jesus wanted to teach was that individual faith in Him, not nationality, was necessary for entrance. This view seems best to me. [source][source][source]
"Christ revealed that unless they prepared themselves to be judged acceptable by the host, they would be excluded from the kingdom when it was instituted." [3][source]
A second view is that the man was at the banquet because he was a believer in Jesus. There the king upon careful examination discovered that he did not have the prerequisite righteousness. Therefore the king excluded him from the kingdom. In other words, he withdrew the man"s salvation. The problem with this view is that it involves the withdrawing of salvation. This view is untenable in view of Scripture promises that once God gives the gift of eternal life He never withdraws it ( John 10:28-29; Romans 8:31-39). [source][source][source]
A third view is that the loss of salvation is not in view, but the loss of eternal reward is. The man has eternal life. The wedding garment does not represent salvation but good works with which the believer should clothe himself in response to the demands God has on his or her life. [source][source][source]
"There is no suggestion here of punishment or torment. The presence of remorse, in the form of weeping and gnashing of teeth, does not in any way require this inference. Indeed, what we actually see in the image itself is a man soundly "trussed up" out on the darkened grounds of the king"s private estate, while the banquet hall glows with light and reverberates with the joys of those inside. That is what we actually see. And that is all!" [4][source]
However the term "weeping and gnashing of teeth" as Jesus used it elsewhere seems to describe hell, the place where unbelievers go (cf. Matthew 8:12; Matthew 13:42; Matthew 13:50; Matthew 24:51; Matthew 25:30; Luke 13:28). This term was a common description of Gehenna, hell (4Ezra7:93; 1Enoch63:10; Psalm of Song of Solomon 14:9; Wisdom of Solomon 17:21). The works just cited in parentheses are Hebrew pseudepigraphal and apocryphal books. [3]3 [source]