Man is sinful through his stubborn self-will and cannot on his own, despite his good works or philosophy, have fellowship with a Holy God. Sin cannot come within the presence of God.

Salvation cannot be earned or simply a state of mind.

"Indeed, there is not a righteous man on earth who continually does good and never sins."
(Ecclesiastes 7:20)

"...for all have sinned and fall short of the glory of God,..." (Romans 3:23)