Lawful oaths and vows
This article by Rodney Kleyn provides a Reformed exposition of Lord's Day 37 of the Heidelberg Catechism, addressing the lawful use of oaths and vows as an application of the third commandment. Through careful biblical and theological analysis, Kleyn distinguishes between oaths and vows, explains why swearing by God's name is permissible under proper conditions, and critiques the rash vows of medieval Roman Catholicism, offering practical guidance for Christian conduct.
Lord's Day 37 Question 101. May we then swear religiously by the name of God? Answer. Yes; either when the magistrates demand it of the subjects; or when necessity requires us thereby to confirm fidelity and truth to the glory of God and the safety of our neighbor; for such an oath is founded on God's Word, and therefore was justly used by the saints both in the Old and New Testament. Question 102. May we also swear by saints or any other creatures? Answer. No; for a lawful oath is calling...
Full article available on sb.rfpa.org