I don’t think we can ever say too much about the importance of an active exercise of mind and heart at the communion service. . . .
Holy Communion demands us of private preparation of heart before the Lord before we come to the table. We need to prepare ourselves for fellowship with Jesus Christ the Lord, who meets us in this ceremony. We should think of Him both as the host of the communion table and as enthroned on the true Mount Zion referred to in Hebrews 12, the city of the living God where the glorified saints and the angels are.
The Lord from His throne catches us up by His Spirit and brings us into fellowship with himself there in glory. He certainly comes down to meet us here, but He then catches us up into fellowship with Him and the great host of others who are eternally worshipping Him there.
We are also to learn the divinely intended discipline of drawing assurance from the sacrament. We should be saying in our hearts, ‘as sure as I see and touch and taste this bread and this wine, so sure it is that Jesus Christ is not a fancy but a fact, that He is for real, and that He offers himself to be my Saviour, my Bread of Life, and my Guide to glory. He has left me this rite, this gesture, this token, this ritual action as a guarantee of this grace; He instituted it, and it is a sign of life-giving union with Him, and I’m taking part in it, and thus I know that I am His and He is mine forever.’ That is the assurance that we should be drawing from our sharing in the Lord’s Supper every time we come to the table.
And then we must realize something of our togetherness in Christ with the rest of the congregation. . . . [We should reject the] strange perverse idea . . . that the Lord’s Supper is a flight of the alone to the Alone: it is my communion I come to make, not our communion in which I come to share. You can’t imagine a more radical denial of the Gospel than that.
The communion table must bring to us a deeper realization of our fellowship together. If I go into a church for a communion service where not too many folk are present, to me it is a matter of conscience to sit beside someone. This togetherness is part of what is involved in sharing in eucharistic worship in a way that edifies.
—J. I. Packer, “The Gospel and the Lord’s Supper,” in Serving the People of God, vol. 2 of Collected Shorter Writings of J. I. Packer, 49-50