It is crucial for the new life and spiritual growth to belong to the Biblical church. In order not to cool down in love and faith we should listen to the preaching of the Word of God and have a fellowship with other Christians.
As we see from the book of Acts, early Christians, preaching the gospel of Jesus Christ, they built the church, through which God functioned in His power and wisdom.
"To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God" (Ephes. 3:10)
The Church is called the Body of Christ, and the body consists of many parts. So the church consists of many people. The Bible teaches the mandatory membership of the church.
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