Follow this link to a wonderful homily by Father Martin Fox, in which he compares Jesus' advice to "Take up the cross and follow me" to the encouragement we have heard: "Offer it up!"
Here's just a bit of it--but do go read it all!
I know, you wonder, how can that do any good?
How can my cold, last week,
contribute to the salvation of the world?
That’s not for us to know, is it?
But we do know the Lord said:
you want to share the glory? Share the Cross!
Offer it up!
Notice what a great act of humility this is:
We’re proud to bring an impressive gift;
instead, we have to bring something so insignificant!
Parents, when you teach your children
these small sacrifices,
you are starting them on the path to heroic virtue:
this really is the school of sainthood!
This is how we begin to learn the courage it takes
to be a priest, to be a nun,
to be a faithful spouse and parent;
to be a missionary, to be a police officer or a soldier;
to be a worker for justice in countless ways.