Have you ever wondered that if Adam would not have sinned, and lived a perfect sin free life, if He would have inherited eternal life ?
If Adam [Mankind] had remained unfallen, without transgression, then He nor men in him could have entered that Kingdom of Eternal Glory to which all believers in Christ were destined before the foundation Matt 25:
34 Then the King will say to those on His right hand, Come, you blessed of My Father, inherit the kingdom prepared for you from the foundation of the world:
2 tim 4:18
And the Lord shall deliver me from every evil work, and will preserve me unto his heavenly kingdom: to whom be glory for ever and ever. Amen.
At best, the life we had in Adam was earthly 1 cor 15:
46Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual.
47The first man is of the earth, earthy; the second man is the Lord from heaven.
48As is the earthy, such are they also that are earthy: and as is the heavenly, such are they also that are heavenly.
49And as we have borne the image of the earthy, we shall also bear the image of the heavenly.
50 Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption.
So if Adam would have continued perfect in the flesh and blood he was created in, He could not inherit the kingdom of God, prepared for the sheep from the foundation, remember, at his best, Adam was still flesh and blood..
hebrews 2 :
14Forasmuch then as the children are partakers of flesh and blood [In Adam], he also himself likewise took part of the same; that through death he might destroy him that had the power of death, that is, the devil;
And scripture says this 1 cor 15:
50Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption.
So Man at His best unfallen state in flesh and blood, cannot inherit the kingdom of God..
As Jesus said, except a man is born again, he cannot see the kingdom of God, even Adam, in His unfallen state needed to be born again if He was to inherit the Kingdom of Glory..