In the Great Commission, Jesus gives instruction based on His authority to call his Kingdom to Himself:
And Jesus came and said to them, “All authority in heaven and on earth has been given to me. Go therefore and make disciples of all nations,baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age.”
What is taught and commanded regarding the Supper?
And when the hour came, he reclined at table, and the apostles with him. And he said to them, “I have earnestly desired to eat this Passover with you before I suffer. For I tell you I will not eat it until it is fulfilled in the kingdom of God.” And he took a cup, and when he had given thanks he said, “Take this, and divide it among yourselves. For I tell you that from now on I will not drink of the fruit of the vine until the kingdom of God comes.” And he took bread, and when he had given thanks, he broke it and gave it to them, saying, “This is my body, which is given for you. Do this in remembrance of me.” And likewise the cup after they had eaten, saying, “This cup that is poured out for you is the new covenant in my blood.
The Apostle Paul weighs in on the importance:
For I received from the Lord what I also delivered to you, that the Lord Jesus on the night when he was betrayed took bread, and when he had given thanks, he broke it, and said, “This is my body which is for you. Do this in remembrance of me.” In the same way also he took the cup, after supper, saying, “This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me.” For as often as you eat this bread and drink the cup, you proclaim the Lord’s death until he comes.
To offer the Supper is a means of preaching the Gospel, and we are exhorted to do so.
Brothers, sisters — let us come to the table today with repentant hearts and childlike faith.
But may all who seek you
rejoice and be glad in you;
may those who love your salvation
say continually, “Great is the Lord!”
As for me, I am poor and needy,
but the Lord takes thought for me.
You are my help and my deliverer;
do not delay, O my God! (Psalm 40:16-17 ESV)