In Leviticus 5, there are some deep theological principles that begin to come to life. We’ve heard it said that our body is the temple of God. Here in the OT, we get a picture of how and where sin was cleansed. The purification offering was made in the temple in order to eradicate the stain of sin. For the believer today, that cleansing is done inside of us.
We also know that Jesus Himself is referred to as the true High Priest. Though Aaron and his family tried their best to fill this role in the OT, it would be Jesus who exemplified the perfect High Priest.
But when Christ appeared as a high priest of the good things to come, He entered through the greater and more perfect tabernacle, not made with hands, that is to say, not of this creation; 12 and not through the blood of goats and calves, but through His own blood, He entered the holy place once for all, having obtained eternal redemption.
Hebrews 9:11-12 NASB
The death of Jesus has absolutely and completely purified us from the sin in our lives. It is so complete, in fact, that it never needs to be repeated. However, we also can gather from this chapter that our sins still do have consequences that defile the temple (our own bodies). The Christian today is commanded not to grieve the Spirit but to walk in the Spirit and be filled with the Spirit. The Holy Spirit is the person sent by Jesus to provide daily victory over sin.