We must never think that sin doesn’t matter, even a little sin. Just a little sin can numb the soul, like a pinching spot in your shoe that rubs and rubs on your foot until a callus forms. The result is exactly the same for your soul — a callus builds up and you become hardened, blinded; your soul no longer feels the danger of its sin and thus does not turn away or avoid it. Eventually you can lose the Holy Spirit entirely.
For those who do realize they’re slipping into that kind of an attitude, turn at once to Christ and seek His forgiveness. Ask Him to forgive you, not for your own sake or because you’re so sorry, but for His pity’s sake — for the sake of His holy, bitter sufferings and innocent death. Then you will find plentiful mercy and never-failing forgiveness.
9 He said, “Go and tell this people: “‘Be ever hearing, but never understanding;
be ever seeing, but never perceiving.’
10 Make the heart of this people calloused;
make their ears dull
and close their eyes.
Otherwise they might see with their eyes,
hear with their ears,
understand with their hearts,
and turn and be healed.” (Isaiah 6:9-10 niv)