The wedding feast of the Lamb is the Eucharistic celebration

"“Blessed is the one who will dine in the kingdom of God.”  (Luke 14: 15)

The dinner is the Church gathered in the Eucharist.

The Amplified Bible has this translation for the above scripture:
"(Happy, fortunate, and to be envied) is he who shall eat bread in the kingdom of God!"

The Eucharistic bread is available for us every single day.  Most of us can dine in the Kingdom of God every day.  Some do this.  But how many feel truly fortunate and to be envied for the privilege of dining in the Kingdom?

"Then the angel said to me, “Write this: Blessed are those who have been called to the wedding feast of the Lamb. And he said to me, “These words are true; they come from God.”  (Revelations 19: 9)

The wedding feast of the Lamb is the Eucharistic celebration.  To accept the gift to dine in the Kingdom, the Eucharist, is to accept the ultimate sign of God's favor.

"This I know: God is on my side.
I praise the word of God,
I praise the word of the LORD.
In God I trust, I do not fear.
What can man do to me?"  (Psalm 56: 10 - 12)

The Eucharist is the sign of God's abiding love for us.