We as Christians, all join ourselves with Christ's sacrifice at Baptism and the Sacraments. We Catholics call it "Sharing the sufferings of Christ." More importantly we share in the glory of Christ. We have access to the grace that he acquired at His Passover. It all has to do with the "power of the keys." Jesus gave St. Peter the Keys of the Kingdom of Heaven and told him that whatever he bound on earth would be bound in Heaven and whatever he loosed on earth would be loosed in Heaven. Therefore, the Holy Father, Pope Benedict XVI has the power to dispense indulgences and we have access to the treasury of the never ending grace that Jesus earned when He died and the cross and rose from the dead. Everything is described in the Catechism of the Catholic Church. It really is worth reading. I would highly recommend it to you.
We don't join ourselves. God unites us to Christ. But the work of salvation is entirely the work of Christ alone.
"This union of the mother with the Son in the work of salvation..."
That sentence from the RCC catechism is blasphemy. No one joins in the work of salvation. Men are gifted with salvation. Men are graced with salvation. Men are chosen for salvation. Men do not, ever, never, aid Christ in His work on the cross.
He did it all. That's why salvation is by unmerited grace through faith and not debt.
Just wanted to thank you for your post, and mention the Gospel I remembered, when I read it:
Christ told us “Store not up for yourselves treasures on earth, where moth and rust do corrupt, and thieves break in and steal; but store up for yourselves treasures in heaven.”
If He told us to do that, and then gave us His neverending grace, then your posts make perfect sense, and I thank you for participating in this discussion.