Illustration of what is meant by us "offering up" our sufferings and trials to God in prayer.

The simplest picture I can think of that helps me is when a little child falls down and skins his or her hand, the child will run to and hold the injured limb up to his or her parent and say “Look, Mommy or Daddy, it hurts!”. Often with tears. And the child waits for the response of the parent. We can do that with God and see what He will do with it. In that very act we are entrusting God with our hurtful situation like a little child. We are uniting our sufferings with those of Jesus and God will turn them into something beautiful and to the benefit of others as well, in time.

And actually God does more than that when we entrust Him with our sufferings. He changes us and our hearts instead of becoming hard become soft and pliable in His hands. Our compassion for the sufferings of others increases because we allow ourselves to feel their pain since we acknowledge ours before God.