John 8:43
Why do you not understand what I say? It is because you are not able to hear my word.
Romans 3:11
there is no one who understands, no one who seeks for God.
1 Corinthians 6:16
Or do you not know that he who joins himself to a prostitute becomes one body with her? For, as it is written, "The two shall become one flesh."
Ephesians 4:18
they are darkened in their understanding, alienated from the life of God because of the ignorance that is in them, due to the hardness of their heart;
Hebrews 12:8
If you are left without discipline, in which all have become partakers, then you are illegitimate children and not sons.