How do we know the doctrine of the true church is true?

The doctrine of the true church is confirmed through the testimony of Scripture, where Christ is depicted as the head and foundation of the church. He established the church on Himself, ensuring that the gates of hell will not prevail against it. Furthermore, the New Testament writings emphasize that believers are part of Christ's body, united in His salvation and righteousness. As believers, we are called to gather where the truth of the gospel is proclaimed, and where the ordinances are faithfully practiced, thereby affirming the truth of our doctrine.