Concise Bible Dictionary:

The wrath of God against all ungodliness and unrighteousness of men is plainly declared in scripture, and will surely fall upon the children of disobedience (Rom. 1:1818For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness; (Romans 1:18); Col. 3:66For which things' sake the wrath of God cometh on the children of disobedience: (Colossians 3:6)). The fierceness of that wrath is spoken of (Rev. 16:1919And the great city was divided into three parts, and the cities of the nations fell: and great Babylon came in remembrance before God, to give unto her the cup of the wine of the fierceness of his wrath. (Revelation 16:19)). How vain then for the false teachers to speak only of the love of God, and to say that because “God is love” there will be mercy for all eventually. There is grace for all now, but there is as surely a day of wrath coming, for God is righteous.