Is the wages of sin our natural death?

Concerning a fallen nature:

16 And the Lord God commanded the man, “You are free to eat from any tree of the garden, 17 but you must not eat from the tree of the knowledge of good and evil, for on the day you eat from it, you will certainly die.” (Genesis 2:16-17)

One way of looking at God's command is to combine it with this:

For in Your sight a thousand years are like yesterday that passes by, like a few hours of the night. (Psalm 90:4)

which is repeated here:

Dear friends, don’t let this one thing escape you: With the Lord one day is like a thousand years, and a thousand years like one day. (2 Peter 3:8)

So Adam and Eve did die on the same "day" that they ate of the fruit, if that day is taken figuratively to be a thousand years. A second example of this principle is found in the story of Noah:

6 When mankind began to multiply on the earth and daughters were born to them, 2 the sons of God saw that the daughters of mankind were beautiful, and they took any they chose as wives for themselves. 3 And the Lord said, “My Spirit will not remain with mankind forever, because they are corrupt. Their days will be 120 years.” (Genesis 6:1-3)

Biblical genealogies show that people after Noah still live much longer than 120 years, but the maximum ages steadily declined. However, if you follow the chronologies forward 1,000 years from that statement, you get to a point a decade or two after the death of Moses. Moses died at age 120 years. Nobody in the Bible after Moses ever again lived longer than 120 years.

So Adam and Eve went from immortal, to mortal with a lifespan of up to a thousand years, and their descendamts eventually to a lifespan no greater than 120 years. This shows a progressive corruption of the human genome, a physical manifestation of a changed nature, which presumably has a spiritual component as well, as claimed by the Apostle Paul in his writings, when he talks about the "flesh" or "sin nature".

As an interesting scientific aside, consider this command:

Do not make an idol for yourself, whether in the shape of anything in the heavens above or on the earth below or in the waters under the earth. 5 You must not bow down to them or worship them; for I, the Lord your God, am a jealous God, punishing the children for the fathers’ sin, to the third and fourth generations of those who hate Me, 6 but showing faithful love to a thousand generations of those who love Me and keep My commands. (Exodus 20:4-6)

It has recently been shown that acquired characteristics related to the environment may be passed down from parents to children via "epigenetic" markers. These markers, if not reinforced by the children, fade after three to four generations. So a trait like susceptibility to alcoholism can be passed down to children of alcoholics due to their parent's bad choices, but it will diminish over the generations if the children and grandchildren choose to reject that habit.

As an example of this working out in the Bible, Cain slew his brother Abel; several generations later, Cain's descendant Lamech was also a murderer.

As one final statement about the nature of man, consider what Solomon, the wisest man to ever live (besides Jesus) said:

Only see this: I have discovered that God made people upright, but they pursued many schemes.” (Ecclesiastes 7:29)

Concerning the "resurrection of the damned".

God cannot contradict himself. He promised to hold a trial for everyone who ever lived:

A river of fire was flowing,
coming out from His presence.
Thousands upon thousands served Him;
ten thousand times ten thousand stood before Him.
The court was convened,
and the books were opened. (Daniel 7:10)

And later:

11 Then I saw a great white throne and One seated on it. Earth and heaven fled from His presence, and no place was found for them. 12 I also saw the dead, the great and the small, standing before the throne, and books were opened. Another book was opened, which is the book of life, and the dead were judged according to their works by what was written in the books.

13 Then the sea gave up its dead, and Death and Hades gave up their dead; all were judged according to their works. (Revelation 20:11-13)

Since God promises a trial, everyone must appear in court, and if you are a corpse in the ground, how can you hear the charges? How can you be made aware of the judgment? These two realities - death for sin and a conscious judgment - require that all people be resurrected, prior to sentencing. Trials in absentia are not a thing in the Bible, as Job insisted:

How often is the lamp of the wicked put out?
Does disaster come on them?
Does He apportion destruction in His anger?
18 Are they like straw before the wind,
like chaff a storm sweeps away?
19 God reserves a person’s punishment for his children.
Let God repay the person himself, so that he may know it.
20 Let his own eyes see his demise;
let him drink from the Almighty’s wrath!
21 For what does he care about his family once he is dead,
when the number of his months has run out? (Job 21:17-21)

Job insists that for justice to be properly served, the guilty must see his punishment with his own eyes and see it to come from the hand of God. And when God answered Job, he said:

7 After the Lord had finished speaking to Job, He said to Eliphaz the Temanite: “I am angry with you and your two friends, for you have not spoken the truth about Me, as My servant Job has. (Job 42:7)

God agreed with Job about the need for a trial (and many other things).