Today's homily says that the wedding vestment that the unfortunate guest refused to wear is the attitude and actions of Jesus Himself. God does not limit His reward of eternal life. We have all been invited to the feast. There are some who choose to outright ignore the call for one reason or another. However, this parable seems to warn against those who claim to answer the call, but do so without actually following the path that Jesus laid out us. This seems to address those of us who follow the rituals of our religions without living by the message that God again and again tries to tell us.
God wants us to love one another. Not just some of the time. Not just on Sundays. He wants us to live a life of love in every moment of our lives. That is the wedding vestment that is required of us.