Heidelbasics: Brief Weekly Reflections on the Heidelberg Catechism by Rev. Chuck Meuther
101. But may we swear reverently by the name of God?
Yes, when the magistrate requires it, or when it may be needful otherwise, to maintain and promote fidelity and truth to the glory of God and our neighbor’s good; for such an oath is grounded in God’s Word, and therefore was rightly used by the saints in the Old and New Testaments.
102. May we swear by “the saints” or by any other creatures?
No, for a lawful oath is a calling upon God, that He, as the only searcher of hearts, may bear witness to the truth, and punish me if I swear falsely; which honor is due to no creature.
Some believers regard all swearing as wrong, and so they prefer to use the word “affirm” in pledging something. However, there are examples in Scripture where we find the patriarchs (Gen. 21:24; 31:53–54), Joshua (Josh. 9:15), David (1 Sam. 24:22), and others making oaths.
The point here in the Heidelberg Catechism is that we are not to swear flippantly or make an oath by calling on the name of a venerated saint. Our Lord Jesus Christ reminds us: “Do not take an oath at all, either by heaven, for it is the throne of God, or by the earth, for it is his footstool, or by Jerusalem, for it is the city of the great King. And do not take an oath by your head, for you cannot make one hair white or black. Let what you say be simply ‘Yes’ or ‘No’; anything more than this comes from evil” (Matt. 5:34-36). The prophet says, “How can I pardon you? Your children have forsaken me and have sworn by those who are no gods”
When someone excitedly says, “I swear to God” to give the promise that added oomph, God is not revered or feared. Moreover, such language lands potential judgment on the swearer, because what is implicit in “I swear to God” is “may God deal with me if I do not honor my word.” Now, many will say they do not mean that anymore than when they say OMG that they are putting God’s name in vain.
It is worth remembering, “for out of the abundance of the heart his mouth speaks” (Luke 6:45). May we then hold every word to the captivity of our Lord Jesus Christ and guard our tongues well to the glory of God.