Love God with all your soul and strength,
with all your heart and mind.
And love your neighbor as yourself;
be faithful, just, and kind.
Known best as the "summary of the law" (Mark 12:28-31; Rom. 13:9; Gal. 5:14; James 2:8), the text derives from two Old Testament passages: Deuteronomy 6:5 and Leviticus 19: 18. The almost direct quotation of these biblical texts comes from the hand of Isaac Watts (b. Southampton, England, 1674; d. London, England, 1748), who published his paraphrase in a relatively unknown volume, Divine Songs Attempted in Easy Language, for the Use of Children (1715). Watts originally wrote the poem in four stanzas of varying meter for the children of the Thomas Abney household, where he lived much of his life. The Psalter Hymnal uses only stanza 1, which is the only Scripture stanza and the only one in common meter.
Bert Polman, Psalter Hymnal Handbook
It is vitally important that worshipers understand the role of God’s law among us. God gives his law to us, not so that we can earn his favor by full obedience, for even those converted to God cannot obey this law perfectly. Heidelberg Catechism, Lord’s Day 44, Question and Answer 114 says, “In this life even the holiest have only a small beginning of this obedience.” Instead, says Heidelberg Catechism, Lord’s Day 2, Question and Answer 3, through this law “we come to know [our] misery.”
Yet in their new life of gratitude, God’s children “with all seriousness of purpose, do begin to live according to all, not only some, of God’s commandments” (Heidelberg Catechism, Lord’s Day 44, Question and Answer 114). They measure their good works of gratitude as “those which are done out of true faith, conform to God’s law, and are done for God’s glory” (Heidelberg Catechism, Lord’s Day 33, Question and Answer 91).
In other words, though Christ has fulfilled the law for us, “The truth and substance of these things remain for us in Jesus Christ…[and] we continue to use the witnesses drawn from the law and prophets to confirm us in the gospel and to regulate our lives with full integrity for the glory of God according to the will of God” (Belgic Confession, Article 25). Therefore, the Ten Commandments with explanation are included in the third section, “gratitude,” (Lord’s Days 34-44) of Heidelberg Catechism.