Anger is not sinful, yet the source of one’s anger sometimes does manifest one’s sinful heart. Perhaps the prophet Jonah best demonstrates this truth. When the Lord first approached Jonah about the need in Nineveh, Jonah clearly displayed his displeasure in seeing the Lord work in the lives of the Ninevites. After experiencing the Lord’s chastening, Jonah appeared to have a heart change. Yet, it did not take long before his anger revealed his true feelings and thoughts. As the hearts of the Ninevites were becoming tender toward the Lord, the prophet’s heart was becoming hardened through anger. His anger revealed that he wanted his own will and not God’s.
The Bible teaches us that “if any man be in Christ, he is a new creature” (2 Corinthians 5:17). Following salvation, a man's life should display visible changes as he seeks to put off his former conversation. According to scripture, that former conversation fulfilled “the desires of the flesh and of the mind” (Ephesians 2:3). By the grace of God, change is possible because every believer has been redeemed from his “vain conversation” (1 Peter 1:18). The apostle Paul is a great example. Before meeting the Lord on the road to Damascus, Paul's conversation or lifestyle involved mercilessly persecuting the church (Galatians 1:13). In his new life with Christ, he immediately began preaching the very faith he once destroyed (Galatians 1:23). When a person truly places his faith for salvation in the finished work of Christ, his conversation will change accordingly.
