Natural law is the moral order God inscribed upon the hearts of all humanity, reflecting His own righteous character and serving as a witness to His requirements for justice and goodness. While Reformed traditions agree on its reality, they emphasize that it is fully confirmed and clarified by the written moral law found in Scripture, which points sinners to their need for Christ.
The concept of natural law refers to the moral principles that God has impressed upon the conscience of every human being. As noted in the 1689 LBCF Ch.19 §2, the law that was first written in the heart of man serves as a perfect rule of righteousness. Similarly, the Second Helvetic Confession Ch.12 teaches that this law of nature was originally inscribed by the finger of God, distinguishing it from the specific ceremonial and judicial laws given to Israel. It acts as a universal witness to God’s holiness, demanding conformity to His will.
Natural law does not save; rather, it exposes our rebellion against our Creator. Because we are more sinful than we dared believe, our conscience often reflects a distorted image of God's perfect law. As stated in Romans 2:15, the work of the law is written in the hearts of those who do not have the written law. However, because of our total depravity, we cannot fulfill this law by our own strength. Therefore, the law functions as a schoolmaster, as described in Galatians 3:24, to lead us to Christ. We are more loved in Him than we dared hope, for He alone has perfectly fulfilled the law on our behalf, bearing our curse and granting us His righteousness through faith alone.