What is the purpose of church?

If God has predestined us for salvation, why go to church?

A Christian’s participation in the body of Christ is not for the purpose of being saved (for a Christian is already saved), nor is the gathering of Christians for the purpose of saving unbelievers (though an unbeliever may be saved in the gathering from time to time). The purpose of the church, gathering regularly, is to train up the believer so they may obey and serve Christ, as Paul explains:

Eph. 4:11 And He gave some as apostles, and some as prophets, and some as evangelists, and some as pastors and teachers,
Eph. 4:12 for the equipping of the saints for the work of service, to the building up of the body of Christ;
Eph. 4:13 until we all attain to the unity of the faith, and of the knowledge of the Son of God, to a mature man, to the measure of the stature which belongs to the fullness of Christ.
Eph. 4:14 As a result, we are no longer to be children, tossed here and there by waves and carried about by every wind of doctrine, by the trickery of men, by craftiness in deceitful scheming;
Eph. 4:15 but speaking the truth in love, we are to grow up in all aspects into Him who is the head, even Christ,
Eph. 4:16 from whom the whole body, being fitted and held together by what every joint supplies, according to the proper working of each individual part, causes the growth of the body for the building up of itself in love.

The fact that Christians are chosen by God before the foundations of the world (Ephesians 1:4) does not negate the necessity of gathering together. On the contrary, knowing we were chosen by God to be His children by grace obligates us all the more to seek to please Him, and the regular gathering of saints is the means God has provided to help us do so.

We strongly recommend you listen to our 1 Corinthians Bible study to gain a fuller appreciation of the purpose of the body, gathered and working together.