When Isaiah encountered the Lord, a specific sin came to mind: “I am a man of unclean lips, and I dwell in the midst of an unclean lips” (Isaiah 6:5). It’s not really clear what exactly he meant by this. I wonder if he was referring to the hypocrisy of the Israelites in giving lip service to God but rejecting Him by their actions. This seems to be a theme of Isaiah 1:10-17, where the people of Judah continue to bring sacrifices to the Lord while their “hands are full of blood” (v. 15). Later on in the book, God declares that “this people draw near with their mouth and honor me with their lips, while their hearts are far from me, and their fear of me is a commandment taught by men” (29:13).

In view of this shallow religious practice that did not flow from the hearts of the people, God’s word of prophecy and judgment is very fitting:

“Keep on hearing, but do not understand;
keep on seeing, but do not perceive.”
Make the heart of this people dull,
and their ears heavy,
and blind their eyes;
lest they see with their eyes,
and hear with their ears,
and understand with their hearts,
and turn and be healed.

(Isaiah 6:9-10)

It frightens me to think how easy it is for me to slip into a routine. I can do all the right things and say all the right words and appear to be pleasing the Lord. Maybe I can even fool myself. But God is not fooled. He is the one who tests the heart, and He calls us to follow Him out of a heart that seeks Him first of all. I need to turn to His Word daily in prayer, asking God to soften my heart so that I can turn and be healed.