Really have to keep that verse in context with the following section of 1 Corinthians 15...
1 Cor 15:21-23
21 For since by man came death, by man came also the resurrection of the dead.
How many is that above talking about, because Adam's sin was imparted to all born in the flesh? All born in the flesh, regardless if they are believers or not. And likewise by Jesus Who was born in the flesh like us in order to defeat death for us, by Him came the resurrection, but for whom? just for those who believe on Him?
22 For as in Adam all die, even so in Christ shall all be made alive.
Without the previous verse, this one above is more difficult. Even the wicked all die in Adam's sin. So are all made alive by Christ? Not 'in Christ', but 'by Christ'? This begs the question of when is Paul pointing to, this present world? No, the world to come.
23 But every man in his own order: Christ the firstfruits; afterward they that are Christ's at His coming.
Because of the above verse, many believe this matter by Paul is only pointing to believers on Jesus Christ, and does not include the unbelieving. However, that's men trying to put limitations upon what God's Word really shows...
Lord Jesus said...
John 5:28-29
28 Marvel not at this: for the hour is coming, in the which all that are in the graves shall hear His voice,
29 And shall come forth; they that have done good, unto the resurrection of life; and they that have done evil, unto the resurrection of damnation.
KJV
See that above part about the wicked dead being raised from the dead also on that day?? That "resurrection of damnation" is also about a 'resurrection' from the dead by Christ. The difference Paul later goes into is those resurrected of the 'unjust' will still be subject to the "second death" of being cast into the "lake of fire" after... Christ's "thousand years" reign of Rev.20. Those represent the unsaved nations of Rev.20 which Jesus and His elect will reign over beginning at His future return. Zechariah 14 even mentions leftovers of the nations that fought against Jerusalem at the end will be there, made to come up and worship The KING, Jesus Christ, and keep the feast of tabernacles.
1 Cor.15:24-26
24 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.
25 For He must reign, till He hath put all enemies under His feet.
26 The last enemy that shall be destroyed is death.
KJV
Lord Jesus MUST reign over the unsaved nations with Satan locked in his pit prison, and then loosed one final time to test those unsaved. Then God will rain fire down upon Satan and his host after Christ's 1,000 years reign, and then the GWT Judgment, and death, hell, and Satan cast into the "lake of fire". Then there will be no more death.