Quite honestly, I'm not sure you say anything! A lot of what we say, we say when people really aren't asking questions, and often the best response is silence. But I will address this for anyone who is genuinely wondering about this question.
For starters, the Church is not a man-made institution. Jesus is the One who claimed to be the originator and the head of the church.
...on this rock I will build my church, and the gates of Hades will not overcome it.
It was He who started it, commissioned it, laid down His life for it, and now empowers it by His Spirit to effect His redemptive purpose. The Apostle Paul speaks of Jesus as the "Head" of the Church.
... speaking the truth in love, we will in all things grow up into him who is the Head, that is, Christ . From him the whole body, joined and held together by every supporting ligament , grows and builds itself up in love, as each part does its work.
A study of the New Testament makes it abundantly clear that the Church is made up of redeemed individuals who have placed their hope in Christ for the salvation of their souls. They are not a building, but rather a living organism, called by the Name of Christ and commissioned to go forth in His light and truth.
Now please understand, by stating the above, I'm not so naive as to believe that the church has not been assaulted and, in some cases, commandeered by human control and the corruption of sinful leaders. A study of church history can be a disturbing and discouraging endeavor. But the question each and every Christian needs to ask is: does that history give me the right to reject the Church and toss it aside?
I believe when some people speak despairingly of the Church they are really targeting organized religion which they see as one and the same—but in fact are not the same at all. Organized religion is man's attempt to seize and control that which was originally a divine institution, created by God, to be led by humble and broken individuals who fear God and seek His direction and will. That's a far cry from the human institution of committees and programs that too often take over and usurp the role of God's Holy Spirit.
One thing every redeemed child of God needs to remember is that, like it or not, by placing their hope in Christ for salvation, they have been made members of His Church.
Consequently, you are...members of God's household, built on the foundation of the apostles and prophets, with Christ Jesus himself as the chief cornerstone. Ephesians 2:19-20 (NIV)
Rather than criticizing the Church for its obvious imperfections and opting out of any participation, it ought to be the responsibility of every child of God to prayerfully seek out a place to worship that is in keeping with God's design for the Church in the Scriptures. Here are some of the things you should look for:
1. A Solidly Biblical Statement of Faith. When you attend a church, ask them for a written copy of what they believe. When you get it, compare it to the Word of God to make sure it matches up.
2. Biblical Leadership. Ask questions about how the leadership of the fellowship is set up to run. God gives us a lot of leeway in the New Testament for establishing and running a local fellowship, but here are some important things you should look for:
The pastor shouldn't be a "hireling" whose position is based on the whims of popular vote — neither should he be a dictator with limitless authority.
Leadership should exemplify the fruits of the Holy Spirit (Galatians 5:22-23). Know what those fruits are and expect to see them!
The pastor should be able to teach God's Word in an understandable and clear manner that leaves you feeling well-fed and challenged.
There shouldn't be an undue emphasis on money and the leaders should not be participants in financial extravagance.
3. A Heart for the Community. The fellowship should be actively reaching out to the local community and beyond by sharing the Gospel.
4. Signs of Growth. Is there a balanced mix of younger and older members, with new people coming?
5. Biblical and Balanced Worship. Too many churches engage in unbiblical and unhealthy expressions of worship that only serve to make people feel uncomfortable. The Apostle Paul wrote that everything should be done "decently and in order" (1 Corinthians 14:40). The fellowship you attend should follow this biblical pattern. Not boring, just orderly.
6. God’s Word as the Final Authority. A balanced fellowship shouldn't emphasize emotional responses and personal experience over God's Word. Emotions and experiences are fine, but God's Word should always have the final say.
7. Healthy and Stable Fellowship. The church community should see itself as part of the larger network of the Body of Christ. Avoid a fellowship that leaves you with the impression that they have something that other churches don't have.
There is no such thing as a perfect fellowship. That's because the members are people just like you—possessing sinful hearts. But just because churches are fraught with problems doesn't mean any of us has the right to forsake a place of regular worship with other believers. Instead do your homework, compare what you see with God's Word, and spend time asking for God's leading. He wants you to be connected to a place that's healthy and growing in His grace.