Who is God's enemy?
Satan is God's enemy. .Satan became jealous of God and wanted to be worshipped like him and so he rebelled. Later other angels joined him & became known as demons. Satan also tempted Adam & Eve who sinned and because of that sin, death spread throughout all humankind. So Satan is our enemy also.
While Satan, mentioned above, is the "original enemy" of God... the Bible tells us that God now has "many enemies":
"For as in Adam all die, even so in Christ shall all be made alive. But every man in his own order: Christ the Firstfruits; afterward they that are Christ's at His coming.
"THEN COMETH THE END, when He shall have delivered up the Kingdom to God, even the Father; when He shall have put down all rule and authority and power. For He must reign, TILL HE HATH PUT ALL ENEMIES UNDER HIS FEET. The LAST ENEMY that shall be destroyed is DEATH." (I Cor.15:22-26)
These "enemies" ['echthros'] that God shall put under His feet by the end of His plan, means: "hateful (passively, odious, or actively, hostile); usually as a noun, an adversary (especially Satan)..." (Strong's Definitions).
Anyone who "actively or passively" teaches others "HOSTILITY" toward obedience to God's laws is God's enemy.
"Because the carnal mind [the natural mind of man] IS ENMITY [hostile] against God: for it is not subject to the law of God, neither indeed can be." (Rom.8:7)
"The Bible tells us that Satan-guided men are God's enemies... and that includes His "former enemies" -- those whom He is calling out of the world, His "elect."
"...in due time Christ died for the ungodly... God commendeth His Love toward us, in that, while we were yet sinners, Christ died for us... for if, WHEN WE WERE ENEMIES, we were reconciled to God by the death of His Son, much more, being reconciled, we shall be saved by His Life." (Rom.5:6-10)
The reconciliation of God's "repentant" former enemies makes them His servants... who may, through loyalty and obedience to Him, become His "friends."
"Ye are My friends, if ye do whatsoever I command you. Henceforth I call you not servants; for the servant knoweth not what his Lord doeth: but I have called you friends; for all things that I have heard of My Father I have made known unto you." (John 15:14-15)
Satan is God's original "enemy" [adversary]... but man chose the god of this world to worship and obey in the Garden of Eden, and they rebelled against God's Commandments; and became God's enemies, too. The Serpent's "odious" teaching of hostility toward what God said [and says] opened man's carnal mind to his selfish nature -- and the rest is world history: tears, pain, suffering, misery and death. Man's selfish inability to get along with one another.
So, God is working on removing ALL HIS ENEMIES... and puting them "under His feet": under His Authority and Rulership:
"...he that overcometh, and keepeth My Works unto the end, TO HIM WILL I GIVE POWER OVER THE NATIONS..." (Rev.2:26).
Satan and his angels, as "spirit beings," cannot change and are incapable of "repenting" of their chosen hostility toward God.
God is going to give every man his opportunity to repent, be forgiven their sins ...and to "become His friends." He is [as the passage above states] calling some of His "enemies" now... while the vast majority of God's "mortal enemies" will learn God's Faith, Truth, Grace and Mercy in the Judgment at the Last Day, and cry out for God's Salvation, then.
"...If any man thirst, LET HIM COME UNTO ME, and drink..." (John 7:37).
And there shall also be some "odious, hostile, incorrigibly wicked" men who absolutely refuse and defy God's Authority and His rule over them:
"...Those MINE ENEMIES, which would not that I should reign over them, BRING HITHER, and SLAY THEM BEFORE ME." (Luke 19:27)
This is the "Second Death" Jesus speaks of from which He saves men. It's the changing of man's mortal, dying flesh -- to IMMORTAL SPIRIT -- that shall be incapable of dying any more.
And when all of God's enemies are no more [Satan and his demons removed and the mortal carcases of hostile, wicked men burned in the Lake of Fire; the Second Death - Rev.20:13-15]... then all who still stand and shall be left will be Jesus Christ's immortal brothers and sisters. The Family of God.
And the LAST ENEMY - DEATH - will be gone, also.
Presently... God's enemies are many. They're led by the god of this world, Satan the Devil. The Bible calls them the "children of disobedience."
"... in time past ye walked according to the course of this world, according to the prince of the power of the air, the spirit that now worketh in the children of disobedience..." (Eph:2:2).
The shed blood of Jesus Christ is still working, to "purchase" these disobedient children [God's many enemies] back from their "odious" master... that they might one day be called God's "friends."
But until the end of God's plan is achieved... it remains that God has many, many hostile enemies to put under His feet.
As has already been mentioned in much length, Satan and his angels are enemies of god. However one must not forget that those who have had the Holy Spirit comfirm to them that God exists and then come out in open rebellion against God are also His enemy. Do not think that evil people are enemies of God for they still may believe on His name but chose to go their own way. The final enemy is the flesh.And we shall be changed in the twinkling of an eye.Christ resolved the enmity between the flesh and the spirit.