The word mortal means: subjected to death. It’s a death word.

I could never see God describing the way He made man as mortal.  

God would not and has never said "I made Adam subjected to death."

And although previously I have described Adam as having the ability to die, which is obvious in that Adam did die; However, I also would say the same as with mortality; that God would NOT say NOR has HE ever said "I made Adam with the ability to die." So for me, It’s just not accurate if we are looking at it from God's view and I believe the accurate view is right there for us in scripture; which I will explain.

So, I repent with no shame attached, that I will not continue to explain it as Adam having the ability to die because I see that description causes some to try an attach to it things like mortality and corruption.

We already defined mortality so let’s define corruption. 

Corruption: changed from its original use or meaning to one that is regarded as erroneous or debased.

Can "corruption" describe how God made man? Of course not. He created (ordained) them for His life, designing them to live by persuasion, which is the only way they could be joined to Him (which view is opposed to the slavery of universalism). In the same way they also could not be joined to sin/corruption or death other than by persuasion.

So, what does scripture say? I see scripture gives the accurate description of what happened.

First it tells us that by one man (not an angel) "sin" entered the world. And that death came through sin (only and always). This is from Romans 5:12.

Two verses later in Romans 5:14 it describes what happened in Adam as a "transgression". This is important because Adam’s problem was death and can be seen in understanding the transgression.

Ironically, the word transgressions definition is much like the word corrupt/corruption.

Transgression: a going aside, contrary, a deviation, willful disregard 

It would be willfully leaving the original design. I say willfully because remember that man is a being that God created to function by persuasion. And Adam had not yet been persuaded to eat from the tree of life.

But what exactly was it that Adam was disregarding and going aside from?

Let's establish this first. There can never be a being created that can have a self-sustaining life. Never! Just as a truth, it is NOT possible! 

God is the only source of life. So Adam having no ability to sustain his own life apart from God was not coming behind in anything; his inability did not mean he was in sin, death or corruption, rather he was created by God because God hoped and desired to share His life with him; and promised him His life (eternal life) from the beginning; to persuade him to join himself to Him as one.

John would describe this Word of eternal life as the light and the life of all men (John 1:4). He also would say that Word was made flesh in the resurrected Jesus. Christ, the Word of eternal life that was from the beginning is the light and the life of men; it is the only life there is. 

The word law means teaching and instruction: Christ, being the word of eternal life that is the light and the life of all men; is the only Word/Spirit or teaching and instruction that can fulfill the hope that God had for His life with man; in this we can see the law of God. The promise of eternal life, the instruction of God unto life and immortality; Christ.

So, what was Adam's transgression?

I think one place we can see the answer is in 1 John 3:4;

"Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law."

The word transgression in this verse is "lawlessness". As I explained, Christ is the only Word unto life and immortality; the law of God. To be lawless is to be without Christ; to reject Christ, the Word of eternal life.

Don't we see in Titus 1:2 that God promised eternal life from the beginning? Didn't Adam reject that promise by instead in Genesis 3:7 eating from (the tree of the knowledge of good and evil) a logic that said he could have life another way (sin)?

This is where we see Adam "going aside" (sin), this is where we see Adam transgressing the law of God, Christ. 

This is not only going aside from his original design, this is rejecting the life God offered to give him (the only life there was, as we stated that no being can have life apart from God), this is the way that brings corruption and death to Adam. This is the transgression of Adam, when he married man to death.

Adam, the high priest of the earth was dead; BUT God comes to Adam and renews/reminds him of His promise and that He will be the one to clothe them in His life and immortality;

Showing Adam how He will provide Himself the lamb, coming as a man (our new high priest, the Lord from heaven) to conquer our death.

Jesus Christ, The Word of eternal life, the light and the life of all men has come out of the grave in immortal flesh and bone; Speaking a word to all men;

In this, I believe that we can see that in the heart of God a transgression could only be defined this way (in Adam or you): rejecting the Word of eternal life; the word that was made flesh in Jesus as your only life, hope and inheritance.