The Bible says that God is angry every day. Yet, at the same time He may display His anger, the Bible also says that He is love (1 John 4:8), and righteous (Ezra 9:15), and compassionate (Psalm 86:15), and just (Deuteronomy 32:4), and merciful (Deuteronomy 4:31). The source of God’s anger and the means by which He acts upon His anger sets the standard for what is truly a righteous anger. If man’s righteous acts provoked God to anger, this would signify a sinful nature. The Bible is clear that the opposite holds true. God is provoked to anger by sin (1 Kings 16:2), vanity (1 Kings 16:26), and idolatry (1 Kings 22:53). His righteous anger in each case plainly declares God’s righteous nature. The source of His anger sets forth the only sources by which men should become angry.
A zealous person is contagious, both positively and negatively. The apostle Paul cautioned that the early believers had been zealously affected, but not in a good way. Those who opposed the gospel were adamant, yet they unwisely waged war against the truth. Night and day, they zealously fought in order to hinder the ministry of the believers. Ultimately, their zeal affected the people of God. These believers who started strong were hindered by the enemies' efforts to the point that it affected their race for the Lord (Galatians 5:7). Modern day enemies of the gospel are aware of this potential pitfall for the believers. They often display more zeal than those who knowingly possess the truth. Yet, today's passage also teaches that “it is good to be zealously affected always in a good thing.” Zeal breeds zeal. Zeal in righteousness will yield righteous results.
