I'll show several from one chapter that Paul wrote:
1Co 15:44 It is sown a natural body; it is raised a spiritual body. There is a natural body, and there is a spiritual body.
1Co 15:45 And so it is written, The first man Adam was made a living soul; the last Adam was made a quickening spirit.
1Co 15:46
Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual.
Adam was in the natural body which is mortal NOT the spiritual body which is immortal.
A natural body is intended to die and be raised a spiritual body. Paul knew Adam was not created immortal because he says the first man was made "natural" which was a natural body as opposed to the "spiritual body" which is immortal. The very idea that Adam was created in a natural and mortal body would have been foreign to Paul and any of the disciples.
1Co 15:39 All flesh is not the same flesh: but there is one kind of flesh of men, another flesh of beasts, another of fishes, and another of birds.
1Co 15:40 There are also celestial bodies, and bodies terrestrial: but the glory of the celestial is one, and the glory of the terrestrial is another.
1Co 15:43 It is sown in dishonour; it is raised in glory: it is sown in weakness; it is raised in power:
1Co 15:44 It is sown a natural body; it is raised a spiritual body. There is a natural body, and there is a spiritual body.
1Co 15:45 And so it is written, The first man Adam was made a living soul; the last Adam was made a quickening spirit.
1Co 15:46 Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual.
1Co 15:47
The first man is of the earth, earthy: the second man is the Lord from heaven.
The first man Adam was earthy. That is another way of saying he was mortal.
1Pe_1:24 For all flesh is as grass, and all the glory of man as the flower of grass. The grass withereth, and the flower thereof falleth away:
This speaks of the flesh made from the dust, intended to wither away.
1Co 15:44
It is sown a natural body;
it is raised a spiritual body. There is a natural body, and there is a spiritual body.
1Co 15:45 And so it is written,
The first man Adam was made a living soul; the last Adam was made a quickening spirit.
1Co 15:46
Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual.
1Co 15:47
The first man is of the earth, earthy: the second man is the Lord from heaven.
This does not only apply post fall because Paul is using Adam as the example of the first man who was Earthly, having a "natural body" as opposed to a "spiritual body". Verse 46 makes it clear Adam was NOT in the spiritual body when he was created! This is evidence that Adam was in a mortal, natural, earthly body and NOT in a heavenly, super natural, spiritual body.