Phew, almost up to date (it's just after midnight on day 9).
When my wife and I got married, we found out on the day that a couple of people invited didn't turn up. The back stories to these snubs aren't worth going into, but were disappointing. We ended up inviting a couple of people who were at the service on the spot, and they were able to celebrate with us at the reception. It seemed perfectly biblical to do so, but not quite as much as we didn't go into the street to invite total strangers.
In Matthew 22:1-14, Jesus describes the Kingdom of Heaven (a polite way for a Jew to refer to the Kingdom of God, not some idea about life in the clouds playing harps) as a wedding feast. These always involved an entire village (see the wedding at Cana in John's gospel) and were huge affairs - even more so when a king was involved. Christianity can be seen as dour, naysaying, fun stealing and killjoy, but the biblical picture is far more nuanced. There's so much feasting used in parables (and who doesn't like eating?)
The parable has the king inviting people to a celebration, which is met with weak excuses and violence. Instead, those who were invited were unworthy, and the kings slaves hit the streets to invite everyone. This is the message we see again and again, not the religious or the elite but the poor, those who were excluded or who made bad choices - the 'good and the bad' as the NASB says.
This passage seems to me to describe Jesus ministry - although some read this as judgement day with the 'weeping an gnashing of teeth'. While this is in other places applied to an idea of last judgement, here it does seem to refer to the reaction to Jesus ministry. The one not in wedding clothes is not the person who thinks they are ok their whole lives but finds they are not at the resurrection (not initially here, but ultimately true) but the hangers on who don't really buy Jesus' agenda (the likes of Judas?)
So many are called, but few are chosen to me is not part of the Calvinism-Arminian debate, but simply that even the temple authorities, Pharisees and Sadducees are called, but mostly it is the taxcollecter, prostitute and 'sinner' who are chosen.
That all said, this should remind us that simply being at church or being a good person no more makes you part of the kingdom than living in a garage makes you a car! Whatever else you believe about the basis on which people are 'chosen', the key is to accept the invitation, and that comes with idea that you then don't pay for your wedding meal, it is what is given to you. Join in the celebration. As Easter approaches, we need to think of our faith as one long celebration. Even if the Messianic banquet is not yet arrived, we live as if it were coming. Every coming together in community does that, and Communion, the Lord's Supper, Mass, Sacrament or Ordinance is a vivid reminder of this.