It might be easier for us to view God as being like a two-sided coin. On one side, God is pictured as the Holy Judge who sentences all men to death for their sin. On the other side, God is love, as seen by the fact that He sent His only begotten Son to take our "death sentence." These two views can be seen in a single verse: "For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord" (Rom. 6:23)! In other words, our "works" earn us a death sentence, but His Son's work on the cross of Calvary, allows Him to offer us the gift of eternal life!
The Just God is often known for His wrath. The phrase, "the wrath of God," appears ten times in the entire Bible, and surprisingly, it appears only once in the Old Testament (Ps. 78:31). Nine times in the New Testament, five of which are in the Book of Revelation, "the wrath of God" is presented (Jn. 3:36; Rom. 1:18; Eph. 5:6; Col. 3:6; Rev. 14:10, 19; 15:1, 7; 16:1).
Those who view God as being "God is love" (1 Jn. 4:8, 16), are aware that there are two purposes for the biblical writers to warn us of God's wrath: 1) God is trying to prevent us from sinning; and 2) God is trying to bring to repentance those who ignored His warning. In the Book of Revelation, John describes horrendous judgments on mankind, and then, almost mournfully, states that the world will refuse to "take the hint," and repent (Rev. 9:20, 21; 16:9, 11)!
It is inevitable that the "wrath of God" will result in many men, women, boys, and girls spending eternity in the Lake of Fire, but those who are cast into the torment intended for Satan, will have no one but themselves to blame: God has faithfully warned them of His certain, and eternal, wrath!
"God's wrath" is both a warning, and a certainty for those who reject Jesus!