They argue that God is loving and merciful, and therefore God's anger is merely a bogey with which to frighten naughty children. But how do we know that God is loving and merciful? The heathen do not believe that He is. Nor does nature clearly and uniformly reveal the fact. The answer is, we know God to be such, because His Word so affirms. Yes, and the same Bible which tells of God's mercy speaks of His wrath, and as a matter of fact, refers more frequently (much more so) to His anger than it does to His love.
A.W. Pink