We have considered several different models for worship, all of which capture different aspects of what it means for the church to meet with Jesus on the Lord’s day. As the chief shepherd-pastor, Jesus is concerned that all of his sheep would be fed and tended (John 21:15-19) as they meet with him.
Different parts of the Lord’s service have different degrees of accessibility to Jesus’s lambs. The sermon is perhaps the least accessible. Confession and singing and tribute-bringing are more accessible to all. But there is only one part of the Lord’s service that is accessible to all but the smallest infants, regardless of age (young or old) or mental capacity.
Thus, weekly communion: because Jesus wishes to feed all of his lambs as they come to worship him, so that all from the least to the greatest share in the experience of meeting with and receiving from him.