Mark 7:15 states the principle that defilement comes from within, which Mark 7:23 concludes with 'all these evils come from inside'.

In Mark 7:18, Jesus explains that nothing external defiles, providing the reasoning for the conclusion in Mark 7:23.

Titus 1:15 echoes Mark 7:23's teaching: impurity comes from within — to the corrupted, nothing is pure; their minds and consciences are defiled.

Isaiah 55:7 calls the wicked to forsake their evil thoughts and ways — the very inner evils Mark 7:23 says defile — offering repentance and pardon.