Since the Mosaic law orders the death penalty for crimes such as cursing one's parents (Ex. 21:17), Sabbath-breaking (31:14), and homosexuality (Lev. 20:13), we might think that judges in ancient Israel executed everyone who worked on the Sabbath, dishonored their parents, or committed sexual sin. In turn, this makes us prone to believe the new covenant use of God's law is incongruous with the old covenant. After all, we do not execute people for many of the crimes that merited death before Christ came.
Knowing that premeditated murder was the only crime for which capital punishment was always required helps us better understand the Mosaic law. Aside from capital murder, it seems death was the maximum sentence when it was prescribed in the law, not necessarily the required one. Judges were to weigh the circumstances of each offense and consider the offender's hard-heartedness before wisely applying the standards of the Mosaic law. The law's structure confirms this. For example, Numbers 15:32–36 records the case of a man who gathered wood on the Sabbath. God had earlier revealed death as the penalty for Sabbath-breaking (Ex. 31:14), but the people still asked the Lord what to do. If judges had to execute all Sabbath-breakers, the inquiry would have been unnecessary. From the hesitation to apply the death penalty without further revelation, we may infer that Israelite judges could sometimes impose a penalty besides death for Sabbath-breaking. Since God ordered execution in this specific instance, the man gathering wood must have been especially bold and impenitent in his lawbreaking.
Case laws in the Mosaic code also support our thesis. Life is complex, with no two moral or legal dilemmas being exactly the same. To help His people apply His statutes properly, God gave examples of particular situations that illustrated how His law was to be used (see, for example, Ex. 21:28–32). The Lord did not directly address every possible life situation, for then His law code would have been infinite in length and impossible for human beings to master. Yet principles can be drawn from the case law for every situation, and judges were to apply these principles wisely whenever they heard a case.
Although first-degree murder is not the unforgivable sin, those who commit it forfeit their right to physical life in every instance. The careful application of the death penalty indicates that we consider life to be as precious as God does.
Many people accuse Christians of being inconsistent in our stance against homosexuality because we believe it immoral, like the Old Testament, but, unlike the Old Testament, we do not call for the death of those who commit sexual sin. This charge falls flat, for it assumes what must be proven, namely, that God's law requires the death penalty for every crime that it connects to capital punishment. If we know how God's law works, we can answer those who try to trip us up.