The death that Jesus overcame was not physical death. That should be obvious since all die eventually (except those who will be alive when Jesus returns). The death that Jesus overcame is spiritual death.
It could not be any other kind. It surely was not relational. Man/the world suffered death, dust to dust, due to Adam's sin. This mortality spread to all men. Man lost life, an eternal existence. This is precisely why Christ was Incarnated. He took on Himself our human nature, to do what, defeat death, give life, an eternal existance to mankind/the world. Heb 2:14-16 is very specific why He became man and what it accomplished. I Cor 15:12-22 is all about physically dead people being raised. Christ's human nature was raised to life, thus all men in the last day will be raised to immortality and incorruptibility. I Cor 15:53-54.
In scripture, spiritual death is a loss of a relationship. The Second death referred to in Rev 20 at the judgement is NOT physical death but spiritual death. Our baptism is a spiritual resurrection. We are reunited with Christ relationally. How did you ever come to the idea Christ died a spiritual death. He was put into a grave. The resurrection of Lazarus was a fortaste of Christ's own resurrection Lazarus did not die a spiritual death.
Mankind does not die physically because of sin. Physical death is an integral part of the physical creation. Adam didn't die because he sinned. He died because God kicked him out of Eden and he no longer had access to the fruit of the tree of life (Gen 3:22). And death did not spread to all men because Adam sinned; "death spread to all men because all sinned-- " (Rom 5:12).
Adam definitely died physically. Dust to dust cannot have any other meaning. He would return to the elements from which man was created. Mortality is NOT part of creation. Man was created to be eternal. Why would God create man and the creation and call it good, only to also create death which is the destruction of His whole creation.
Death is from Satan, not God. Heb 2:14. The Tree of life is immortality. Adam had a choice between the two. He chose mortality. Christ becomes that Tree of Life by His resurrection.
You are also misinterpreting Rom 5:12, "just as through one man sin entered the world, and death through sin, and thus death spread to al men, because all sinned "through death". Paul never finished the sentence. What you are stating is what Pelagius believed, that each person when they sin also die physically,. become mortal. The next two verses clearify that issue. We don't die for the same reason Adam did, For him sinning came first, for us sinning comes second, namely because we are already mortal. Paul states this also in I Cor 15:56 where he states the sting of death is sin. For Adam it was the other way around, the sting of sin was death.
And Romans 5:18 is not about the sin of mankind. It is about the negation of the effect, i.e., original sin, of Adam's disobedience upon all men. Romans 5:18 says that all men come into this world free from sin. That follows from Romans 5:12 which says that death (spiritual death) of every man comes not from the sin of Adam but from their own sins. 1 Corinthians 15:20-22 is not about salvation at all, but rather about the resurrection of all men, saved or lost, at the end of the age when Jesus returns, similarly Hebrews 2:9; 14-16. I would note here that Satan has no power of physical death; the only instance where we read of Satan bringing about physical death is in the account of Job and there he needed God's permission to bring death to Job's family. The power of death that is in Satan's hands is spiritual death, just as it was with Adam and Eve, and that not directly but through lies and deception.
See above for the explanation of this paragraph also. You have a huge misunderstanding of the fall of man and consequently the salvation of the world/mankind.
I agree. And for what it is worth, that forgiveness of sins is given not to the world, but to each person individually who comes to a belief in God.
Agreed.
You have a really poor understanding of Justification and forgiveness. Those who have been saved have been forgiven and justified. They do not pop out of being forgiven and justified with each sin.
Sin is missing the mark. it is against what God desires for mankind. Every sin is counted against you, and if one does not repent, confess those sins they will condemn one. No one is saved in this life. Our salvation is conditional on remaining faithful.
The only view, that I know of, that teaches this is Calvinism with the preservation of the saints.
Scripture does not support such a view. Sin or how well we resist sin is the test of our faith. Same test Adam had in the Garden before the fall. Obedience to God, or lack thereof.
Forgiveness and justification for those who have been saved is a state of being. You have accepted the RCC interpretation of 1 John 2:6-9 and it is wrong. We can discuss that further if you like.
No one in this life has been "saved" past tense. It is a journey. We are as believers being saved. Our salvation awaits us at the end of our lives; I Pet 1:3-5. We inherit salvation if we have been faithful. Many fall away.