Why do we give offerings? There is, of course, a very practical reason to give money to the church; to provide for the financial needs of the congregation including mortgage payments, utilities, building upkeep, supplies, materials for worship and teaching, and salaries. Unlike a typical business, a congregation doesn't charge for its "services." Rather, those who attend give freely as they are able to support the ministry undertaken by that congregation.
So, is the church just another non-profit? Well, yes and no. As far as tax law is concerned, our congregation is a non-profit organization. Like many non-profits, we are solely dependent on offerings and gifts for our budgetary needs. However, we shouldn't understand the church in this merely secular way, as simply a non-profit business providing a particular religious "product" to members.
The Christian congregation is the body of Christ. He is her Lord. "Jesus said, “Truly, I say to you, there is no one who has left house or brothers or sisters or mother or father or children or lands, for my sake and for the gospel, who will not receive a hundredfold now in this time, houses and brothers and sisters and mothers and children and lands, with persecutions, and in the age to come eternal life" (Matt. 10:29-30). In a typical business transaction when you pay a $1 you get a $1 worth of product or service. Is that true in church? The gifts that Christ gives are free in terms of cost yet priceless in terms of value. The tithes and offerings we give to the church in response to Christ's love are multiplied more than a hundredfold as we receive back from the Lord as pours upon us the riches of His grace. Our worldly riches may be few or many, but the riches of eternal life are countless. Thus, we Christians give generously as the Lord has generously given to us. He takes what we give and returns it a hundredfold.