Malachi is the last book of the Old Testament, written about 430 B.C. The temple Haggai and Zechariah helped rebuild was standing, but many hearts had drifted. The book reads like a conversation: the Lord says something, and the people push back with “Wherein?” (“How?”) again and again (Malachi 1:2, 6–7; 2:17; 3:7–8). The Lord’s very first words are “I have loved you” (1:2), and His invitation is “Return unto me, and I will return unto you” (3:7). Priests had been offering blind, lame and sick animals, the leftovers nobody wanted (1:8). The Lord wanted their best, because He wanted their hearts.
Malachi 3:8–12 is the Old Testament’s great tithing passage: “Will a man rob God?… In tithes and offerings.” The Lord invites us to “prove me now herewith” and promises to “open you the windows of heaven, and pour you out a blessing.” Today tithing is one-tenth of our increase (Doctrine and Covenants 119:4). It helps build temples and meetinghouses and share the gospel around the world. Children pay tithing on money they receive by filling out a donation slip and giving it to a member of the bishopric, or online with a parent’s help. Nine- to eleven-year-olds can handle the math and the “why”: blessings are often quiet ones like peace, gratitude, stronger faith and help when it’s needed, not a promise of riches. Some children don’t receive money yet, and some families are going through hard times: never ask who pays. Keep it joyful; tithing is a way to say thank you and to trust the Lord.
Malachi also looked ahead to Jesus Christ. A messenger would prepare His way (3:1), fulfilled by John the Baptist (Matthew 11:10). The Savior would be like a refiner’s fire and fullers’ soap, purifying His people (3:2–3), and those who love Him are written in “a book of remembrance” and called His “jewels” (3:16–17). When the resurrected Savior visited the Nephites, He gave them Malachi 3–4, because their families had left Jerusalem before Malachi wrote (3 Nephi 24–25; 26:2).
Malachi ends with a promise: “I will send you Elijah the prophet” to turn the hearts of the fathers and the children to each other (4:5–6). When the angel Moroni quoted it to Joseph Smith in 1823, he worded it differently: Elijah would reveal priesthood power, and the promises made to the fathers would be planted in the hearts of the children (Joseph Smith—History 1:38–39). On April 3, 1836, Easter Sunday and one week after the Kirtland Temple was dedicated, the Savior appeared there to Joseph Smith and Oliver Cowdery, followed by Moses, Elias and Elijah. Elijah gave them the sealing keys (Doctrine and Covenants 110). Because of those keys, families can be sealed forever and ordinances like baptism can be done for people who died without them. Paul mentioned baptism for the dead too (1 Corinthians 15:29). Youth can receive a limited-use temple recommend starting in January of the year they turn 12. Be sensitive: some children’s families aren’t sealed, some are adopted or blended, and some are going through hard things. Every child belongs to Heavenly Father’s family, and every child can learn about and help their ancestors.