What does the Bible say about man's sinful nature?

Man's sinful nature is most vividly depicted in the events surrounding the crucifixion of Christ, especially in the mockery and mistreatment He endured. These actions illustrate the deep-rooted depravity within humanity that leads to a hatred of the only one who can save us from our sin. From Adam's fall in the garden, mankind has been rebellious against God's righteous rule, which is evident in the efforts to assert independence from divine authority. As stated in Mark 15, the Roman soldiers' treatment of Jesus is a reflection of this fallen nature; they expressed their disdain for Christ's kingship by humiliating Him, showcasing humanity's natural enmity towards God.