What does this phrase mean?
We are priests of God by our baptism. We are not ministerial priests, who offer up the sacrifice of Christ upon the altar at Holy Mass. But, as non-ministerial priests, we do offer something to God: our bodies, our actions, our labor, and even our sufferings.
We can we “offer it up” simply by asking God, in the midst of our suffering, to join our suffering to Christ’s, and to use our suffering.