What is the purpose of Church?

This is a controversial topic for sure- has been for thousands of years. Not looking to stir up a wasp's nest here (pun intended), just providing some of my contemplations. My exploration of the subject started with the Great Commission being taught at church, in tandem with trying to understand Reformed Theology, and then followed by an article on the seeker sensitive church over at CRI. Those three thoughts merged and this question came about. This is how it changed my understanding of the Great Commission and the purpose of church.

The Great Commission
Matthew 28:16 So the eleven disciples went to Galilee to the mountain Jesus had designated. 28:17 When they saw him, they worshiped him, but some doubted. 28:18 Then Jesus came up and said to them, “All authority in heaven and on earth has been given to me. 28:19 Therefore go and make disciples of all nations, baptizing them in the name of the Father and the Son and the Holy Spirit, 28:20 teaching them to obey everything I have commanded you. And remember, I am with you always, to the end of the age.”

For years this has always been presented to me in a fashion that seemed to change the text to say 'Go and make believers', not 'Go and make disciples'.
Contextually, the commission is telling the disciples to go and make more disciples. Which means taking those whom the Lord has ordained and instructing them in the same way Christ instructed His disciples, whom He hand picked.

How do you know who is ordained, or who you should present the Gospel to? This is the Reformed Theology part. If only it were as easy as Spurgeon is attributed with saying:

"If God would have painted a yellow stripe on the backs of the elect I would go around lifting shirts. But since He didn't I must preach "whosoever will" and when "whosoever" believes I know that he is one of the elect."

In obedience to Jesus' commands we definitely should proclaim the Gospel message. (Col 4:2-6) But how and when? Is church the place to do it? My quick response is, Yes! Proclaim the Good News in church.. duh. It benefits Christians to hear it too. But who is there with you, other believers or non believers? And why are they there? To be discipled, trained and educated, or just entertained like some 'seeker sensitive' churches. I hate that term. Don't get me wrong, some churches that are 'seeker sensitive' have great ministries. And just because you are a big church with good music doesn't mean you are doing it all wrong. But it's the seeker sensitive issue that got me thinking more about what church should be like, what the purpose of it is. Is it to edify they body of Christ or reach the unsaved with the Gospel? Do both, sure, but do you try to reach the unsaved so hard that you entertain more like the world we are called to be separated from.
Sacrificing the Bible for entertainment isn't really in line with "I have become all things to all people . . . for the sake of the gospel" (1 Cor. 9:22-23) We are not to be of the world. [1John 2:15] The Gospel isn't entertainment- it's grace, it's repentance, it's forgiveness.

In summary:
We don't need 'seeker sensitive' churches. God seeks us, we don't seek him. Rom. 3:11 "there is no one who understands, there is no one who seeks God." The Lord does the work; we obey him by encouraging and teaching believers. We are blessed to be used by God in response to His commands. Go out into your community and love, live, outreach and present the Good News! As God reveals himself to man, bring them as brothers and sisters adopted in Christ into the fold for worship, instruction, correction, and fellowship (2Ti 3:16). The Church is the body of believers, not a facility built for entertainment and fluffy feel good messages.

Romans 16:25 Now to him who is able to strengthen you according to my gospel and the proclamation of Jesus Christ, according to the revelation of the mystery that had been kept secret for long ages, 16:26 but now is disclosed, and through the prophetic scriptures has been made known to all the nations, according to the command of the eternal God, to bring about the obedience of faith – 16:27 to the only wise God, through Jesus Christ, be glory forever! Amen. -The Apostle Paul

Amen.