1 corinthians 15:45 is talking about Adam and Jesus, the last Adam.
- Adam was created by God and behold He saw that it was very good. He was created as "good", perfect and without sin.
- Adam was the originator of human race
- Eve was tempted and fell and Adam with him fell too
- Devil was given all power and glory of them(all kingdoms of the world) through the fall of Adam[luke.4:6]
- Adam and Eve were now fallen and sinful. They were spiritually dead[eph.2:1 & col.2:13].
- last Adam was created by God( power of the Highest shall overshadow Mary[luke.1:35]) in Mary's womb as sinless.
- one could interpret, that last Adam was the originator of new human race, new breed, through faith in Him by grace[eph.2:8].
- Devil fell( long period in between ) and tempted last Adam( eq. in the wilderness[matt.4:1] ), but He did not fell.
- Jesus, last Adam was given all power in heaven and in earth through the work of Jesus in Galvary[matt.28:18 & col.2:15]
The reason why I think this notion about Jesus being the last Adam is important, is that
I got an idea that Jesus, the Christ is last Adam as Paul describes in 1 corinthians 15:45.
It came to my mind that Jesus was called the last Adam in the Bible, when I thought about the statement from a bishop of orthodox church of Finland that the starting point of orthodox perception of a human is the goodness of man. Then I thought about Adam before the fall and thought what it must have felt like to live then as perfect, sinless human. I maybe tried to go back to good old days before the fall and dreamed to be like that Adam, but now I realised that I don't have to identify myself to the Adam before the fall but to the last/second Adam. And I don't have to follow the first Adam before the fall, but last/second Adam who was as Adam was before the fall. That's why he is called last/second Adam, because he was as Adam was before the Fall; without sin in Him. If I would identify myself and would try to follow the first Adam before the fall, then it would be impossible for me or otherwise I would be living in my own strength, because Adam was tempted like I was, but failed, but now we have better Adam; last Adam, who as sinless, overcame all temptations and was saviour and redeemer for all man.
So the reason why I think this notion about Jesus being the last Adam is important is that Paul hold the Scriptures at the time including story of the genesis and especially the fall at least authentic. And Paul now out of the scriptures at the time, defined who Jesus was/is; the last Adam. But He is not only last Adam, because Bible defines Him by many other titles as well. So it is important, because Paul defines Jesus as a new originator of the human race, whom we can identify ourselves; the last Adam. It is a title which defines Jesus as "new originator" of "new breed" among human race. He is fully human, yet at the same state as Adam was before the fall; without sin.
Herein is our love made perfect, that we may have boldness in the day of judgment: because as he is, so are we in this world.[1 john.4:17(KJV)]
And now we are new breed; as he is, so are we (almost) in this world, through faith in Jesus by grace.
Another question is, what apostle John meant by saying; as he is, so are we in this world? Maybe he meant that faithful are imitators of Christ, Christlike, christians.
If you have Dake's annotated reference bible you find there in page 174 of NT side a analysis titled as
"12 contrasts: Adam-Christ( rom.5)".
There Dake give 12 contrasts, where he compares Adam and Christ( last/second Adam).