Christians believe that God has revealed Himself as Triune: simultaneously singular and plural, living in community with Himself. This is unlike any other religion’s concept of God, and is impossible to describe or comprehend. In the same way, the gathering is a theological reflection of the nature of God; it reflects the unity and community of the Trinity. All are individuals, but are spiritually woven into one entity called the Body of Christ.
The first reason Christians must gather is to embody our identity. Though each person comes to God individually (Rev. 3:20), the Apostle Peter refers to Christians as a plurality, calling us a race, a priesthood, a nation, and a people (1 Pet 2:9-10). The Apostle Paul identifies Christians as members of the same body, and individually members of each other (Rom 12:4-5). Unlike God, an individual can’t be a community apart from gathering with others. Christians are to assemble and install themselves into the Body of Christ, just as a Stonecutter fits stones into a wall (Eph 2:20-22). Further, Protestants believe that although one person is not a priest, the gathered Christians do constitute the priesthood of God. One person is not a body (in the group sense), but the Christian community is the Body of Christ. Christians must gather in order to embody their scriptural identity.
If Christians embody a spiritual priesthood as they gather, then what are they to do? A second reason Christians must gather is to perform their vocation. Since Christians are a priesthood, they should do ‘priestly’ things, like offer sacrifices. Peter tells Christians “you, also, as living stones, are being built up as a spiritual house for a holy priesthood, to offer up spiritual sacrifices acceptable to God through Jesus Christ” (1 Pet 2:5). What, then, are the spiritual sacrifices? There are four passages that specifically use sacrifical language in the New Testament. The first is to offer the sacrifice of thanks and praise (Heb 13:15). The second is the act of giving (Phil 4:18). The third is the sacrifice of Self (Rom 12:1-2), while the fourth is the sacrifice of service (Phil 2:17).
A third reason Christians must gather is to accomplish their mandate. Followers of Christ have received not only a vocation, but also marching orders, and these orders cannot be obeyed in solitude. We are commanded to gather in order to encourage one another (Heb 10:24) and to make disciples (Mat 28:19-20). Included in this process is evangelizing, teaching and baptizing. We simply can’t accomplish this in isolation.
Finally, Christians gather to experience the presence of Christ. Jesus promised that He would be present when his followers gathered in his name (Matt. 18:20). When we gather for worship, we, in a very real sense, stand at the intersection of time and eternity. Brueggemann calls this act “world-making” because corporate worship constructs a world in which the members can “viably, joyously, and obediently live.” World-making is done by God “through sacramental activity which God has authorized.” For example, at the last meal with his followers, Jesus provided a way to draw near to him through the use of memory and hope. As Christians speak and reenact the words “as often as you eat this bread and drink the cup, you proclaim the Lord’s death until He comes” (1 Cor 11:26), there is both remembrance of His death and anticipation of his return. Both memory and hope facilitate a drawing near of God and Man (Jam 4:8).