Which is better? Picture this: a small group of believers who gather together faithfully every Sunday and at least once during the week to study, pray, and listen to each other. They know each other well, they care about each other, they love each other. Someone gets sick, everyone knows, sends flowers, and drops a phone call. Someone doesn't show up on a Sunday, someone stops by for a visit to check in. Someone moves away, their absence is felt deeply. Someone new joins, their presence is felt immediately.
Now picture this: A large group of believers by the hundreds stream in to gather to worship and praise God. They are passionate about reaching the community. With combined resources and numerous outreach programs they are able to influence the community in a powerful way. Many who would never dare step foot in a small traditional church where they don't fit in, come and feel welcome among a diverse crowd. There are ministries for every age group from toddlers to teenagers to seniors. A large staff and facility allow for lots of classes, programs and small groups.
Which is better? Neither. What often happens is one model feels superior to the other: "Big churches are compromising the truth," or "Small churches are all dying." In doing so we can miss the beauty and blessing of each. Scripture never gives us a numerical command for church size. That's because God allows for diversity here. Both play an important role in the Church (capital "C").