This article is an exposition of Lord's Day 8 of the Heidelberg Catechism. The doctrine of the Trinity is the foundation of the Christian faith. This is so because this is how God has revealed Himself to His Church. This article shows the biblical foundation of this teaching and the importance of this doctrine for the church in her worship of God.

In this article on Lord's Day 8 of the Heidelberg Catechism, the relation between Christianity and other religions is discussed, specifically evolutionism and Islam. The image of God and love in evolutionism and Islam is focused on. The equality of religions is also mentioned.