Ezekiel 44 takes place either during the Millennium or the Great White Throne Judgment. However, from certain details, it seems that God is referring to the actual ancient Israelites who failed Him under the Old Covenant.
It appears that, when the Israelites rise in the second resurrection, God will make them perform what they failed to do originally! He will give them a chance to repent of their unfaithfulness, to make up, as it were, for the sins of the past. They will know every time they lift a bullock onto the altar, every time they keep the gate, every time they make the showbread, every time they fulfill any of their responsibilities to God, that they failed in their first attempt to keep the terms of their covenant with God.
That is bearing iniquity! They will be reminded in every action that they have sinned and are a sinful people. It will be a hard lesson for Israel, but they will learn it well.
God says in Isaiah 43:21, "This people I have formed for Myself; they shall declare My praise." Finally! In the end, when God gives them the complete package of spiritual blessings, the Israelites will glorify God as He intended from the beginning, fulfilling their ultimate purpose.
Richard T. Ritenbaugh
Why Israel? (Part Two)