Paul did NOT say "'by' Christ shall all be made alive." All mankind are inherently "in Adam," since all mankind are literal descendants of Adam, without any choice on their part, BUT "all mankind" are NOT inherently "in Christ" that requires a personal conscious action by each individual.
Here are some verses where Paul stresses being "in Christ."
Ephesians 1:10 That in the dispensation of the fulness of times he might gather together in one all things in Christ, both which are in heaven, and which are on earth; even in him:
NOT “in Christ””in Him” NOT gathered together in one.
Romans 3:24 Being justified freely by his grace through the redemption that is in Christ Jesus:
NOT “in Christ” NO redemption.
Romans 8:1There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit.
“Walk after the flesh” NOT “in Christ” there IS condemnation.
Romans 8:2 For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death.
NOT “in Christ” NOT free from the law of sin and death.
Romans 12:5 So we, being many, are one body in Christ, and every one members one of another.
NOT “in Christ” NOT a member of the body.
1 Corinthians 1:30 But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption:
NOT “in Christ” NO sanctification, NO redemption.
2 Corinthians 5:17 Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new.
Not “in Christ” old things NOT passed away NOT made new.
Galatians 3:26 For ye are all the children of God by faith in Christ Jesus.
NOT “in Christ” NOT children of God.
Ephesians 2:13 But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ.
NOT “in Christ” NOT ”made nigh” still far off.
2 Timothy 1:1 Paul, an apostle of Jesus Christ by the will of God, according to the promise of life which is in Christ Jesus,
NOT “in Christ” NO promise of life.
2 Timothy 2:10 Therefore I endure all things for the elect's sakes, that they may also obtain the salvation which is in Christ Jesus with eternal glory.
NOT “in Christ” NO salvation.
2 Timothy 3:15 And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.
NOT “in Christ” NO salvation.
And when we get to the end of the book.
Revelation 21:4 And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away.
Revelation 21:5 And he that sat upon the throne said, Behold, I make all things new. And he said unto me, Write: for these words are true and faithful.
Revelation 21:8 But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death.
Rev 21:4 says “there shall be no more death” in vs. 5 Jesus said “Behold I make all things new.” Vs. 4 “No more death” but 4 verses later, Rev 21:8 says 8 groups “shall have their part in the lake which burns with fire and brimstone: which is the second death.” If there is “no more death” after vs. 4 then those thrown into the lake of fire in vs. 8 do not die although it is still called the “second death.”.
Revelation 22:11
11 He that is unjust, let him be unjust still: and he which is filthy, let him be filthy still: and he that is righteous, let him be righteous still: and he that is holy, let him be holy still.
There is no mention of salvation after Rev 22:14.
Revelation 22:15
15 For without are dogs, and sorcerers, and whoremongers, and murderers, and idolaters, and whosoever loveth and maketh a lie.
Revelation 22:18
18 For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book:
Revelation 22:19
19 And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book.
2 More verses "The End"