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:
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.