Theme: The one true God is three distinct persons; worship him, he is beyond our understanding

Link to Belgic Confession Article 8

"The Trinity is a mystery, not merely in the Biblical sense that it is a truth, which is formerly hidden, but is now revealed; but in the sense that man cannot comprehend it and make it intelligible....[the church] has never tried to explain the mystery of the Trinity, but only sought to formulate the doctrine of the Trinity in such a manner that the errors which endangered it were warded off." [Louis Berkhof, Systematic Theology]