Continuing off of another thread:
Is there a different salvation in the OT than in the NT or was it always by grace through faith in Christ?
The sin and death problem is first and foremost an INTERNAL problem with all who are "in Adam." All in Adam are dead in sins - SPIRITUALLY SEPARATED FROM GOD thus separated from the LIFE of God, the LOVE of God, the HOLINESS of God and the LIGHT of God.
Let those four things sink in? Separation from God's LOVE, LIGHT, LIFE and HOLINESS.
1. LOVE = If you are separated from the love of God then the carnal mind is at ENMITY with God and LOVES darkness more than light and will not come to the light.
2. LIGHT = The sinners loves DARKNESS and cannot UNDERSTAND the things of God
3. HOLINESS = Is not subject to the law of God and neither indeed can be. There is none good, no, not one.
4. LIFE = dead in tresspasses and sins - "alienated from the life of God"
This is not the problem that just started after the cross, but this was the problem that characterized Adam "in the day" he sinned. This is what characterizes every child of Adam from Genesis 4 to 2019. This means that every single human "in Adam" has this four-fold problem and cannot serve God until this four-fold problem is resolved within them.
This fourfold INTERNAL problem - sinful condition (depravity, death, darkness, enmity) can only be resolved by a supernatural creative act by God that reverses spiritual separation from God to spiritual union with God as it is separation from God that cause separation from God's life, love, light, and holiness. That supernatural work is called SPIRITUAL UNION or new birth. Apart from spiritual union there is no other alternative human condition but darkness, death, depravity and enmity.
Salvation designed by God remedies this four fold problem without which, fallen man LOVES darkness more than light and WILL NOT come to the light, is at ENMITY with God and is not subject to the law of God; and is not GOOD nor can do GOOD in God's sight, and cannot UNDERSTAND the things of God