There are two theological terms Christians can struggle with—sovereignty and grace. If we fail to fully grasp grace as the unmerited favor of God bestowed on sinners, we run the risk of thinking grace is somehow earned. On the other hand, if we misunderstand God's sovereignty, we run the risk of thinking it doesn't matter how we live because God is sovereign. Everything we do is foreordained so why does it really matter? This is what Paul is dealing with in this passage, not exactly sovereignty and grace, but he is dealing with closely related concepts—God's faithfulness and justice.