Wrong.
"If your brother or sister sins, go and point out their fault, just between the two of you. If they listen to you, you have won them over. But if they will not listen, take one or two others along, so that 'every matter may be established by the testimony of two or three witnesses.' If they still refuse to listen, tell it to the church; and if they refuse to listen even to the church, treat them as you would a pagan or a tax collector." (Matthew 18:15-17)
If the church simply meant a group of believers then Jesus would have ended it after saying bring the 2 or 3 witnesses because that would have been the church if we go by your definition. The Church is an organization that settles disputes and keeps believers on the straight and true path.
Nobody would say a building is the Church because a building is simply a building. But in the current state of Christianity you could not say it is every single Christian either. Jesus established a single infallible church and gave it the power to rule on matters of faith. The Keys of Heaven were given to Saint Peter and he said "whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven." If somebody refused to listen to this church Jesus established he told them to treat them like Tax Collectors and Pagans (Excommunication).