If, however, Adam and Eve did not possess something that allowed them to live forever, then God's concern about them acquiring this ability is justified. He did not want his greatest creation, in a rebellious state of mind like the devil's, to immortally exist in unhappiness and misery.
Humans, simply by virtue of their birth, do not possess ANYTHING that is immortal. The Bible is crystal clear that the ability to live forever is a gift from God to those who live a life obedient to him (1Corinthians 15:50-55, 2Timothy 1:9-10, Romans 2:7, 6:23, etc.). This is sometimes referred to as conditional immortality.
Is it in the Bible?
Interestingly, the terms "immortal" and "immortality" are not found in the Old Testament, either in our English translations or in the original Hebrew text. The word "immortal" is used only once in the entire Bible in translations such as the NKJV, NIV, NASB and others. It is found in 1Timothy 1:17 where it is used to refer to one of God's (not man's) attributes.
The original Greek word from which we get 'immortal' in 1Timothy is aphthartos (Strong's Concordance #G862). It occurs only six other times and is usually translated as 'incorruptible,' meaning something that can never decay or perish, something that endures.
Occurrences of aphthartos in the New Testament.
1Timothy 1:17 - Refers to God as being immortal
Romans 1:23 - Refers to God as being incorruptible
1Corinthians 9:25 - Christians are to obey God in order to receive an imperishable crown
1Corinthians 15:52 - At Jesus' Second Coming believers are resurrected and become incorruptible
1Peter 1:4 - Believers will ultimately receive an incorruptible inheritance
1Peter 1:23 - Believers minds are renewed through God's incorruptible Holy Spirit
1Peter 3:4 - Women should possess the incorruptible beauty of a gentle heart
The attribute of being immortal or having immortality is NEVER applied in the Bible to anything the average human possesses RIGHT NOW on planet earth. This is diametrically opposite the teaching that every human has a soul that continues to live after death.
The soul truth
It was after God brought forth man out of the dirt and gave him life that he became what the KJV calls a "living soul" or a 'living being' according to the NKJV, NIV, NASB, HCSB and other translations, and 'began to live' in the TEV translation. The Hebrew nephesh (Strong's Concordance #H5315) is the word translated as 'soul' and 'being' in the above Bibles. It is used to refer to fish (Genesis 1:20), birds (verse 22), cattle and other animals (verse 24) and of course man (Gen. 2:7).
The Bible does not teach man has or possesses a soul, but rather that man in his entirety IS one!
Psuchë (Strong's #G5590) is a Greek word which is virtually equivalent to the word nephesh in the Hebrew. It is the only New Testament word translated as "soul." It generally means a living, breathing creature, but also adds the implication of being a 'living' creature. Out of the 105 times it is used in the Greek 58 of them are translated as "soul." The word has also been translated as "life" (40 times), "mind" (3 times) and others.
Unfortunately, studying the idea of a soul in the New Testament is complicated by the inconsistency of Bible translations. For example, the NKJV renders the Greek word psuche TWO different ways in two verses. In Matthew 16:25 psuche is translated as the English word LIFE. In the very next verse, psuche is translated as the word SOUL!
The same translation error is also committed by the NIV, NASB, NLT and others for the same verses. More accurate translations like the NRSV, HCSB, HBFV and other consistently use the word 'life' for all four occurences of psuchë in Matthew 16:25-26.
What is man?
The Bible defines Man as a living soul, being, life, etc. that is MORTAL, not immortal. Man possesses no inherent eternal life. When we die we become unconscious and unaware of anyone or anything.
4 The life (nephesh) of every person belongs to me, the life (nephesh) of the parent as well as that ('the life of' - nephesh) of the child. The person (nephesh) who sins is the one who will DIE. (Ezekiel 18:4, TEV)
5 Yes, the living know they are going to die, but the dead know nothing. They have no further reward; they are completely forgotten. 6 Their loves, their hates, their passions, all died with them. They will never again take part in anything that happens in this world. (Ecclesiastes 9, TEV)
The Lord is not praised by the dead, by any who go down to the land of silence. (Psalm 115:17)
No one in the world of the dead can praise you; The dead cannot trust in your faithfulness. (Isaiah 38:18)
Man has never had an immortal soul that allows him to live past death. The only way man can live forever is to repent of his sins, accept Jesus as his Savior, become baptized and receive God's spirit, then live a life of overcoming until death. God is more than willing to give the gift of eternal life (Romans 6:23) to those who love and obey him.