Haggai 2:13
Then said Haggai, If one that is unclean by a dead body touch any of these, shall it be unclean? And the priests answered and said, It shall be unclean. Then said Haggai, If one that is unclean by a dead body touch any of these, shall it be unclean? And the priests answered and said, It shall be unclean.
Haggai's question teaches that uncleanness is communicable by contact, so that whatever is touched by what is unclean itself becomes unclean. The one made unclean by touching a dead body represents a soul corrupted by sin, like a dead body in putrefaction. The washings and sprinklings appointed in the ceremonial law for such defilement were lessons in parable, showing that the purification of a soul dead in trespasses and sins requires a work of regeneration in the heart. That inward cleansing requires the sanctifying power of the Holy Spirit.
Applied to the people and to their work and their offerings, the lesson is that religious services and good works cannot cleanse the sinner or make anyone righteous, nor can company with God-fearing people do so. A person becomes holy and acceptable to God only when Christ's grace cleanses the heart. That cleansing is received through faith and obedience to truth, and comes to those who accept God's light and choose to obey.