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 all 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. For he hath put all things under his feet. But when he saith all things are put under him, it is manifest that he is excepted, which did put all things under him. And when all things shall be subdued unto him, then shall the Son also himself be subject unto him that put all things under him, that God may be all in all. (1Co 15:22-28 KJV)
About the word "all"
Only members of the human race can die in Adam, which would then mean that only members of the human race can be made alive in Christ. The word "all" then changes focus, as Paul goes on to say that Christ must reign, until he has put ALL enemies under His feet. Paul cannot possibly be speaking only about the human race anymore, because he says that the last enemy that will be destroyed is death. The only exception to the word all (which includes ALL) is the Father.
About the word "destroy"
We know that the last enemy that will be destroyed is death. How does one destroy something corruptible? How does one destroy death? Well, by putting on incorruption and immortality! Then the saying that is written will be brought to pass, Death is swallowed up in victory. Death is no more, because it is changed to incorruption and immortality.
So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory. (1Co 15:54 KJV)
Aren't we also destroyed before we are changed and brought into God's family? Of course we are not destroyed in the sense that we will no longer exist, we are simply changed. This is the way God in His wisdom has done it!
We are first made incomplete and spiritually weak:
And the vessel that he made of clay was marred in the hand of the potter: so he made it again another vessel, as seemed good to the potter to make it. (Jer 18:4 KJV)
And as we have borne the image of the earthy, we shall also bear the image of the heavenly. Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption. Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed, In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed. (1Co 15:49-52 KJV)
Satan is a necessary evil, believe it or not:
Now we beseech you, brethren, by the coming of our Lord Jesus Christ, and by our gathering together unto him, That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand. Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition; Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God. Remember ye not, that, when I was yet with you, I told you these things? And now ye know what withholdeth that he might be revealed in his time. For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way. And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming: Even him, whose coming is after the working of Satan with all power and signs and lying wonders, And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved. (2Th 2:1-10 KJV)
So what is it then, will Satan also be changed? Well, he has to be changed because he will enter the Lake of Fire. Will Satan be the only one who is not changed in the Lake of Fire? Will everyone else be purified in the Lake of Fire, except Satan?
And the devil that deceived them was cast into the lake of fire and brimstone, where the beast and the false prophet are, and shall be tormented day and night for ever and ever. (Rev 20:10 KJV)
Notice that the beast and the false prophet are also in the Lake of Fire, along with anyone whose names are not found in the book of life.
And death and hell were cast into the lake of fire. This is the second death. (Rev 20:14 KJV)
Death will be cast into the Lake of Fire and be done away with, changed from death to deathlessness.
The sting of death is sin; and the strength of sin is the law. But thanks be to God, which giveth us the victory through our Lord Jesus Christ. (1Co 15:56-57 KJV)
Sin will be done away with, because there will be no sinners anymore.
If the Lake of Fire is a purifying process (with an end to it), then this has to be true also for Satan and his angels.
I don't agree that this is just a small issue, a "who cares?" subject. However, I'm not trying to be dogmatic, and I am in no way trying to beat anyone in their heads with what I believe. If I am wrong about this, I'm ready to stand corrected!