The Church is deficient at many points today. But there is probably no point where it is more evidently deficient and even explicitly contrary to the teachings of the New Testament than in its neglect of the wrath of God. To judge from most contemporary forms of Christianity, God's wrath is either an unimportant doctrine, which is an embarrassment, or an entirely wrong notion that any enlightened Christian should abandon.
The biblical writers had no such hangups. Rather than suppressing this foundational part of the gospel like so many do today, they spoke of God's wrath frequently, obviously viewing it as one of God's great "perfections"---alongside His other attributes. In the Old Testament, more than 20 words in nearly 600 important passages are used to refer to God's wrath. Other, very different words relate to human anger. These passages are not isolated or unrelated, as if they have been added to the Old Testament at some later time. They are basic and are integrated with the most important themes and events of Scripture.
In the New Testament, there are two main words for wrath: 'thumos,' from a root that means "to rush along fiercely," "to be in a heat of violence," or "to breathe violently," and 'orge,' which means "to grow ripe for something." The New Testament portrays wrath as something that builds up over a long period of time, like water collecting behind a great dam.
We find this understanding of the wrath of God in Romans, where Paul refers to wrath 10 times:
"For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness." (Romans 1:18)
"But after thy hardness and impenitent heart treasurest up unto thyself wrath against the day of wrath and revelation of the righteous judgment of God." (Romans 2:5)
"But unto them that are contentious, and do not obey the truth, but obey unrighteousness, indignation and wrath. (Romans 2:8)
"But if our unrighteousness commend the righteousness of God, what shall we say? Is God unrighteous who taketh vengeance? (I speak as a man)." (Romans 3:5)
"Because the law worketh wrath: for where no law is, there is no transgression." (Romans 4:15)
"Much more then, being now justified by his blood, we shall be saved from wrath through him." (Romans 5:9)
"What if God, willing to shew his wrath, and to make his power known, endured with much longsuffering the vessels of wrath fitted to destruction." (Romans 9:22)
"Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written, Vengeance is mine; I will repay, saith the Lord." (Romans 12:19)
"For he is the minister of God to thee for good. But if thou do that which is evil, be afraid; for he beareth not the sword in vain: for he is the minister of God, a revenger to execute wrath upon him that doeth evil." (Romans 13:4)
"Wherefore ye must needs be subject, not only for wrath, but also for conscience sake." (Romans 13:5)
In each instance the word he uses is 'orge.' His point is not that God is suddenly flailing out in impatient, irritable, ill-tempered anger against something that has offended Him momentarily, but rather that the firm, fearful hatred of God of all wickedness is building up and will one day result in eternal condemnation of all who are not justified by Christ's righteousness.