Leviticus 10:1-3 tells of an incident where Israel learned its spiritual condition.

..Aaron's, God's appointed high priest, sons were hanging near the tabernacle when they decided to take sencers with live coals, poured incense on them and went into the Holy of Holies, which wasn't God's appointed way.

......No one but the High Priest was allowed there and only once a year.

Suddenly the boys fell dead.