Church according to Miriam-Webster's online dictionary:
1: a building for public and especially Christian worship 2: the clergy or officialdom of a religious body 3: a body or organization of religious believers: as a: the whole body of Christians b: denomination <the Presbyterian church> c: congregation 4: a public divine worship <goes to church every Sunday>
Webster defines church according to the way this word is used today. I was taught this same definition as a little boy when I would put my hands together and recite the rhyme: "Here is the church, and here is the steeple; open the door and here are all the people."
Jesus, however, introduced the term "church" with a very different meaning in mind. He used a word "ekklesia" that simply described a group or assembly of people. This is the original definition of the word. He described "church" as those people who were following Him—people walking in allegiance to Him. People. His followers. Nothing more than that…
Nevertheless, by the time I felt called to pastor a church, I no longer questioned how church was done. We started with a building and a core group of Christians. We invited, and planned, and organized, and put together Sunday events. We built more buildings and started more services to invite people to. We developed programs for young and old, men and women, married and divorced. We hired staff and we organized ministry teams.
Without realizing it, we were following human traditions for church life that were developed over the centuries: cathedrals, pulpit-led services, pews, order-of-service, etc. All of these things may be useful in their place (God can use anything), but they have no place in the basic definition of "church…"