A visiting scholar recently picked up a copy of Luther's Small Catechism at one of our ministry events. He started reading at the beginning of the booklet, then came to me with a question when he was at the end of the section about God's Ten Commandments. At that point, the catechism explains the justification of the commands, quoting Exodus 20:5b-6. I include that in my preferred translation. "I, the LORD your God, am a jealous God, visiting the iniquity of the fathers upon the children to the third and fourth generations of those who hate Me, but showing mercy to thousands, to those who love Me and keep My commandments" (Exodus 20:5b-6, NKJV).
This young man asked a very intriguing question. "I don't understand this." He then followed up, "Isn't 'jealous' a negative term in English?"
We do normally think about jealousy as a negative thing. That's quite right. Yet what this passage in the Bible is expressing is a strong attitude on God's part, of protecting his people from harm, no matter who would work against them. Jealousy here means protectiveness. He is the only God for his people, and he wants them to be only his, not anyone else's.
There was a follow-up question, of course. "What if someone has a bad parent but isn't like that bad parent, or what if someone has a good parent but himself goes bad?" That's a really important issue, and one which requires a bit of nuance in the answer. If we treat the verses in Exodus as a statement of absolutes, there's no hope for anyone whose parents hated God. And similarly, it would be impossible that someone whose parents loved God would ever depart from his commands. Once there's one instance, we would fall into an unbreakable loop. Yet that isn't what we can observe.
All fallen humans have a tendency to sin. And all humans other than Jesus have that fallen nature. We don't just tend to sin, we actually do sin. That's enough to merit God's condemnation. And if his condemnation continues for more than one generation, we can perceive that we have effectually ruined the lives of all our descendants.
The reality of a sinful nature is that we absolutely need someone to interfere with our sin, to break its power, and to rescue us. We can't do it ourselves. That's at the heart of Christianity. We don't earn God's forgiveness. We're entrapped in sin. But Jesus, with the power of God, and with a genuine human nature, stepped into the trap, lifted us out, and presented us to God the Father wrapped in his own righteousness, the quality of good, while himself dressing in our filthy rags of disobedience to God. In 2 Corinthians 5:21 the apostle Paul reflects that Jesus, who was a stranger to sin, became sin for us, and that he gave us his righteousness so we could stand before God.
How does this move us? It moves us from the intergenerational curse to the intergenerational blessing. A thousand generations? That's roughly 40,000 years. It's such a long time, so many generations, that nobody would count that high. God's mercy if for generation after generation. And he offers it to you. Even if you and your family have never looked to God in Christ for salvation, he offers to be the God who is your God, and offers that you can be his people. He's jealous for you. He wants to guard and guide you to eternal life. That's the point of all the Scripture. We are to be reconciled to God, because it is his good pleasure.