What are some of the best Catholic Christian explanations you have heard about Ephesians 2:8?
 And hath raised us up together, and hath made us sit together in the heavenly places, through Christ Jesus.  That he might shew in the ages to come the abundant riches of his grace, in his bounty towards us in Christ Jesus.  For by grace you are saved through faith, and that not of yourselves, for it is the gift of God;  Not of works, that no man may glory.  For we are his workmanship, created in Christ Jesus in good works, which God hath prepared that we should walk in them.
We are saved by grace THROUGH faith. From true faith naturally flows good works because faith without works is dead.
I’m a fan of St. Augustin, so I like his Four Anti-Pelagian Writings, “What Do You Have That You Have Not Received?”
But perhaps our opponents may say, “The Apostle distinguishes faith from works; indeed, he says that grace is not given because of works. However, he does not say that it might not be given because of faith.” Indeed this is so, but Jesus says that faith itself is also the work of God, and he commands us to do this work. For the Jews said to him, “ ‘What shall we do, that we may work the work of God?’ Jesus answered and said to them, ‘This is the work of God, that you believe in him whom he has sent.’ ” The Apostle thus distinguishes faith from works, in the way in which, in the two kingdoms of the Hebrews, Judah is distinguished from Israel, though Judah itself is [part of] Israel. But he says that man is justified “by faith … not by works,” in this sense, that faith is first given, and from it the other things may be obtained, which are properly called “works”, by which one lives justly. For he himself also says, “For by grace you are saved through faith, and that not of yourselves, for it is the gift of God,” that is to say, “And when I said ‘through faith,’ even that faith is not from you but is God’s gift.” “Not of works,” he says, “that no man may glory.” It is often said, “He deserved to believe, because even before he believed he was a good man.” This may be said of Cornelius, whose alms were accepted and whose prayers were heard before he had faith in Christ. Yet he neither gave alms nor prayed without faith of some kind. For how did he call on him, in whom he had not believed? For if he could have been saved without faith in Christ, the Apostle Peter would not have been sent like an architect to build him up, although “Unless the Lord build the house, they labor in vain that build it.” And it is said to us, “Faith is from us, the other things pertaining to the works of justice are from the Lord,” as if faith did not pertain to the building of which I speak, as if the foundation of a building did not belong to that building! But if this belongs to it first and foremost, then he labors in vain who seeks to build up faith by preaching, unless the Lord build it up from within by having mercy. Hence, whatever good works Cornelius performed, whether before he believed in Christ or when he believed or after he had believed, should all be attributed to God, lest perchance anyone exalt himself.
The best thing is to read through verse 10!
This is a classic verse out of context issue.
When you read to verse 10 it is exactly the Catholic position.
For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; not as a result of works, so that no one may boast. For we are His workmanship, **created in Christ Jesus for good works, which God prepared beforehand so that we would walk in them. **(Ephesians 2:8-10 NASB)
Galatians also shows this when it speaks of faith working through love which is exactly what the Catholic Church teaches.
For in Christ Jesus neither circumcision nor uncircumcision means anything, but faith working through love. (Galatians 5:6 NASB)
We are saved by Gods gift through our faith in that gift. Faith is an action, a conversion of your life which means works are part of faith.