ORIGINAL SIN? TOTAL DEPRAVITY? OR KINGDOMS...
Receiving eternal life is a matter of kingdoms. The kingdom of God and the kingdom of Satan. Rather than invent complicated theological terms to explain our propensity to sin, why not just use the simple concept of kingdoms taught in the Scriptures?
For example -
When Adam and Eve sinned they were excluded from the kingdom of God and the tree of life.
All of their offspring are also excluded from the kingdom of God and to have salvation they must be delivered (saved) from the kingdom of Satan and restored to the kingdom of God.
Just as Paul described:
Col 1:13 Who hath delivered us from the power of darkness, and hath translated us into the kingdom of his dear Son:
All who are born into the world are born into the kingdom of Satan - their spirits are subject to their flesh and will eventually commit sin - they will follow the king of their kingdom.
1Jn 5:19 We know that we are from God, and the whole world lies in the power of the evil one.
Those whom God calls and believe in Jesus are given power to overcome the evil one.
Joh 1:12 But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name:
Those who believe and obey will receive eternal life - those who refuse to obey will be lost.
That is exactly what John said:
Joh 3:36 He that believeth on the Son hath eternal life; but he that obeyeth not the Son shall not see life, but the wrath of God abideth on him.
Act 2:21 And it shall be, that whosoever shall call on the name of the Lord shall be saved.