If the Bible isn’t the Christian’s source for morality, then the question needs to be asked, “What should be?” The Christian worldview is based on two foundational axioms: 1) God exists, and 2) God has spoken to us in the Bible. If these two presuppositions aren’t the starting point in a Christian worldview, then we’re just like everyone else, trying to find objectivity in a sea of subjectivity.
According to the Bible, man was created in God’s image. Part of that image entails man as a moral being. We are moral agents who make moral choices and are able to differentiate between right and wrong. The basis upon which we differentiate between right and wrong is our knowledge of God’s law, and that knowledge comes from two sources—revelation and conscience. Revelation is self-explanatory. God gave a commandment to Adam and Eve in the Garden. He gave Ten Commandments to the Israelites after the exodus in Sinai, and Jesus boiled those Ten Commandments down to two essential commandments—love God and love your neighbor. All of these represent God’s revelation of His law which is simply a reflection of His moral character to His people.
The Bible also says that God wrote His law on our hearts (Romans 2:15). This is conscience. In other words, even without God’s revelation in the commandments, we intuitively know God’s law based on the fact that we were created in His image. However, due to the fall (Genesis 3), that image is marred and disfigured, including our conscience. So even though we know God’s law through our conscience, we tend to distort it to our advantage. That is why we need revelation.
The Bible, which contains God’s revealed moral will in His law and commandments, is His revelation to His people. As such, the Bible becomes our source of morality because the Bible is the very Word of God in written form (2 Timothy 3:16; 2 Peter 1:21). If the Christian wants to know God’s will, he turns to the Bible. If the Christian wants to discern right from wrong, he turns to the Bible.
What happens if the Christian doesn’t turn to the Bible as his or her source for morality? There are many ways to answer this question, but the bottom line is we all tend to trust our conscience, whether implicitly or explicitly. The human conscience can be likened to an alarm system; it warns us when we transgress our moral standard. The catch is our conscience is only as good as the moral standard that informs it. If it’s not the Bible, then we inevitably inform our conscience by various other means.
The current reigning ‘competitor’ to biblical morality in our society is social consensus. In other words, our morality is shaped and changed by the culture around us. It should be very easy to see that if social consensus is our moral compass, then we have built our morality on a foundation of shifting sand. Social consensus is just that—a consensus. It’s a picture of the general social mores of the day. A generation or two ago, homosexuality, divorce and adultery were still not accepted, even considered sinful. Nowadays, both homosexuality and divorce are normal and adultery isn’t as stigmatized as it once was. Basically what you have with social consensus is what happened to the Israelites a couple generations after conquering the Promised Land: “Everyone did what was right in his own eyes” (Judges 17:6). The people abandoned God, and within two generations they were doing what was evil in the sight of God.
So why should the Bible be our source for morality? Because without it, we are like ships adrift at sea. At the end of the Sermon on the Mount, our Lord said these words: “Everyone then who hears these words of mine and does them will be like a wise man who built His house on the rock. And the rain fell, and the floods came, and the winds blew and beat on that house, but it did not fall, because it had been founded on the rock” (Matthew 7:24-25). The Word of God, the Bible, is the only rock upon which to build morality.