Lucky me! Our associate pastor gave a homily on this, when it was the Gospel reading a couple of weeks ago. It opened up my understanding.
Yes, there are two parts, but they go together, When most of God’s chosen people ignored His invitation, made through His son, and injured and killed His prophets, then He invited the rest of us in.
But to participate in the feast, we have to put on the proper garment. That garment is reconciliation with God - yes, the Sacrament of Reconciliation.
By my personal extension, it means obedience to God.
By my further extension, it means that saying “I accept Jesus as my personal Savior” isn’t enough! That’s accepting the invitation, but not putting on the garment.
From my experience, I’d say that most Non-Catholic Christians agree with the above, though they may disagree with the garment being the Sacrament.
God bless us all,
Ruthie