"We … continually remind each other of these things. The wealthy among us help the needy, and we always keep together. For all things with which we are supplied, we bless the Maker of all through his Son Jesus Christ and through the Holy Spirit. On the day called Sunday, all who live in cities or in the country gather together in one place, and the memoirs of the apostles or the writings of the prophets are read, as long as time permits. Then, when the reader has ceased, the president [I think this means whichever brother is presiding, but no one knows for sure] verbally instructs and exhorts to the imitation of these good things.
Then we all rise together and pray, and … when our prayer is ended, bread and wine and water are brought, and the president in like manner offers prayers and thanksgivings according to his ability, and the people assent, saying Amen. There is a distribution to each and a participation of that over which thanks have been given, and to those who are absent a portion is sent by the deacons.
They who are well to do and willing give what each thinks fit, and what is collected is deposited with the president. He helps the orphans, widows and those who, through sickness or any other cause, are in need. [He helps] those who are in bonds and the strangers sojourning among us. In a word [he] takes care of all who are in need.
But Sunday is the day on which we all hold our common assembly, because it is the first day on which God, having made a change in darkness and matter, made the world. On the same day Jesus Christ our Savior rose from the dead. For he was crucified on the day before that of Saturn [Saturday], and on the day after that of Saturn, which is the day of the Sun, he appeared to his apostles and disciples and taught them these things." - Tertullian, c. A.D. 210
"Nobody can do as much damage to the church of God as the man who is within its walls, but not within its life." - C.H. Spurgeon
"Labor together with one another. Strive in company together. Run together; suffer together, as the stewards, assessors, and servants of God." - Ignatius, c. A.D. 110
"Take heed to come together often to give thanks to God and show forth his praise. For when you assemble frequently in the same place, the powers of Satan are destroyed and the destruction at which he aims is prevented by the unity of your faith. Nothing is more precious than peace, by which all war, both in heaven and earth, is brought to an end." - Ignatius, c. A.D. 110
"The Bible knows nothing of solitary religion." - John Wesley
"Associate with sanctified persons. They may by their counsel, prayers, and holy example, be a means to make you holy." - Thomas Watson
"Satan always hates Christian fellowship; it is his policy to keep Christians apart. Anything which can divide saints from one another he delights in. He attaches far more importance to godly intercourse than we do. Since union is strength, he does his best to promote separation." - C.H. Spurgeon
"Satan watches for those vessels that sail without a convoy." - George Swinnock
“Some Christians try to go to heaven alone, in solitude. But believers are not compared to bears or lions or other animals that wander alone. Those who belong to Christ are sheep in this respect, that they love to get together. Sheep go in flocks, and so do God’s people.” - Charles Spurgeon
“Has it ever occurred to you that one hundred pianos all tuned to the same fork are automatically tuned to each other? They are of one accord by being tuned, not to each other, but to another standard to which each one must individually bow. So one hundred worshipers met together, each one looking away to Christ, are in heart nearer to each other than they could possibly be, were they to become 'unity' conscious and turn their eyes away from God to strive for closer fellowship.” - A.W. Tozer