What is 'Church'?

The Church is the total community of God’s people gathered in and through Jesus Christ. Scripture refers to this community as the ‘body of Christ’ with Christ as the head (1 Cor. 12:12-13). We are initiated into this community through our baptism, and are continually nourished within this community by the Holy Spirit through God’s Word and Jesus' own body and blood in the Lord’s Supper.

What is the visible church?
“The visible church is the whole number of those who use the Word of God and profess the Christian faith, but among whom, beside the true Christians, there are also unbelievers.”
-An Explanation of the Small Catechism

Who gathers the church?
God gathers the church through his Word and Spirit. 

Who rules the church?
Christ is the head of the church and he rules with the Gospel, the good news, that in Jesus Christ God is reconciling the world to himself, restoring all creation back to good.

Where does the word 'church' come from?
The word ‘church’ comes from the Greek word ekklesia which means 'assembly' or 'called-out ones.'

How does the Church fit into God's grand plan? 
In the beginning God walked in fellowship with humanity, but Adam and Eve rejected this fellowship seeking to be their own gods. Because of this, sin entered the world and the harmonious relationship between God and humanity was fractured. In the person and work of Jesus Christ, God is rebuilding a new community, the Church, and restoring fellowship between God and humanity. This new community reflects God’s one reconciling work which will be fully realized in the new heavens and the new earth when all things will be put back to rights.

Scripture References:

God’s Promise to Be Present With Believers
    -Matthew 18:20
    -Matthew 28:20
    -1 Corinthians 10:16-17
    -1 Thessalonians 2:11-13

Christian Worship Focuses on Jesus
    -John 5:23
    -John 8:31-32
    -Acts 4:12
    -1 Corinthians 11:25 (communion)
    -2 Corinthians 5:14-15
    -Galatians 3:24-29
    -Philippians 2:9-11
    -1 John 1:7

For Further Reading:

Meaningful Worship by James L. Brauer
An Explanation of the Luther's Small Catechism (Questions 169-179)
The Augsburg Confession (Article VII and Article VIII)