Romans 3:4 says, “let God be true, but every man a liar.” Perhaps this truth serves as the foundational reason why God warned believers not to place their trust in man. Though the primary reason, it is not the only reason. In Psalm 146:3 the Lord warns, “Put not your trust in princes, nor in the son of man, in whom there is no help.” The real needs of mankind cannot be satisfied by man, even the best of men. Those who put their trust in man do so in disobedience to the Lord which results in their own personal harm. Psalm 118:8-9 twice stresses that “It is better to trust in the LORD.” An improper trust in man is, in many ways, a departure from the Lord (Jeremiah 17:5).
Man-made religions have always unwisely taught followers to establish their own righteousness. In the garden in Eden, Adam and Eve clothed themselves with fig leaves in an attempt to cover their nakedness caused by sin. Men built the tower of Babel hoping that this device could help them reach into heaven. The Bible describes man’s righteousness as “filthy rags” (Isaiah 64:6). Today's passage tells of a people who went about to establish their own righteousness by refusing to submit to God’s righteousness. Man-made religions all err in the same way. They think that some work or act of obedience can somehow establish a level of righteousness that will ultimately and eventually satisfy God. Yet, the Bible points out the repeated futility of failing to submit to the righteousness of God.