In a concise fashion, here’s a capsule understanding of the “why, when and what” of the gathered church in the New Testament:
They met on the first day of the week* to celebrate the resurrection through adoration, instruction, participation, and edification. (John 20:1; Acts 2:1; Acts 5:12)
Specifically, here are various Scriptures supporting these 4 elements that are staples to the corporate meeting of the church:
Instruction (preaching and teaching)
Acts 2:14; 1 Cor. 15:1; 1 Tim. 4:13; 2 Tim. 4:1-2; Titus 2:1
Proper leaders teaching proper doctrine.
Adoration (prayer and worship)
Acts 3:1; Acts 2:42; Acts 4:23-31; 1 Tim 2:1
Responding to who God is and what he has done with all that I am.
Identification (baptism and Communion)
Acts 2:41; Acts 2:42; 1 Cor. 11:17-34; Acts 16:15, 33; Matthew 28:19-20
Remembering God’s ordinances till he comes.
Edification (gifts and service)
Acts 4:32-37; 1 Cor. 16:1; 1 Cor. 12:7, 25; 1 Cor. 14:26; Heb. 10:25
Using what I’ve been given to build each other up.
There is lots more — tons more! — on this subject that I have elected not to dive into. No doubt you could write volumes on each of these areas and develop all kinds of ways to implement them. So don’t read more or less into what I have written. My goal is to simply show that there are some staple items — building blocks — that form the outline for a corporate gathering of the church and provide the biblical basis for them. May these guide us as we structure our regular time together as the body of Christ.
*While the first day of the week was the day initially used, Paul seems to later say, in Romans 14 and 1 Cor. 8, that we have freedom to gather on other days as well, or even instead; the day of the week on which the church meets now seems to be a matter of conscience and faith and not an issue of law.