Nobody wants to talk about the wrath of God. God has emotions, just like us. When he gets mad he exhibits his wrath. If it wasn't for his Son Jesus Christ he would have wrapped up this whole universe in one big ball of fire when Adam sinned. Thankfully, God knew that Adam was going to sin and that Jesus would atone for his sin and the sins of the whole world before the foundation of the world, Revelation 13:8.
For now, God sees ALL THINGS in his Son Jesus Christ. Those that are "In Christ" will not experience God's wrath, but those that are not "In Christ" will in the judgment.
"He that believes on the Son has everlasting life: and he that does not believe on the Son shall not see life; BUT THE WRATH OF GOD ABIDES ON HIM" John 3:36.
Paul said that the wrath of God would come upon the "Children of disobedience" Ephesians 5:6 also Colossians 3:6 and then he said that the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, WHO HOLD THE TRUTH IN UNRIGHTEOUSNESS, Romans 1:18. That would include all of the cults and all religions that have not obeyed the Gospel of Jesus Christ, Romans 10:16. To obey the Gospel means to cease from your own works or religion and to rest or trust in the work of Christ for your salvation.
"For we which do believe have entered into HIS REST, as he has said, As I have sworn in my wrath, IF THEY SHALL NOT ENTER INTO MY REST: although the works were finished from the foundation of the world" Hebrews 4:3.
This scripture also pertains to the Israelites that were disobedient in the wilderness and would not enter into the promised land because of unbelief and disobedience, Hebrews 3:10. What it amounts to is do you believe God? God sends Jesus into the world to be our savior. All that Jesus is and all that Jesus does is for our justification and our salvation. By faith in him and in his Gospel we have eternal life, John 3:16. Do you believe God? If you believe God, then it is the Gospel plus nothing. If it is the Gospel plus something, then it is no longer the Gospel and you have not entered into his rest.