This article is an exposition of Lord's Day 23 of the Heidelberg Catechism. The author explains why justification is found in Christ alone by faith alone, drawing out the comfort this brings to the believer.

This article is a copy of Zacharinus Ursinus's exposition of the Heidelberg Catechism Lord's Day 23, which shows that righteousness has to do with conformity with the law, and that justification is the application of this. Evangelical righteousness is when God imputes Christ's righteousness to the believer and declares the believer just on the basis of the complete work of Christ.