"... according to the riches of His grace which He lavished on us."
*God is totally other-oriented, generous beyond measure. The lavishing of His favor is according to the riches of His grace. What an amazing difference between out of and according to! Were Bill Gates, the Microsoft billionaire, to give me a sum out of his wealth, it could range from a penny to almost all he has. But if he were to give according to his financial capabilities, I'd be an instant millionaire, at least. He would be parting with a sum in proportion to his store.
The spiritual application is mind-boggling. The infinitely-great Creator of all that is, the One Who spoke everything into existence, and sustains it all by His omnipotence, has seen fit in the giving of His Son to show His elect favor in salvation according to the riches of His grace! Who can fathom a proportion of infinite riches? Who can truly grasp such giving? And to then consider the recipients of such lavishing...!
Reminds me of II Samuel 9:7,8, where the crippled son of Jonathan, Mephibosheth, is shown favor by King David. "Do not fear, for I will surely show kindness to you for the sake of your father, Jonathan, and will restore to you all the land of your grandfather Saul; and you shall eat at my table regularly," said the king. Mephibosheth, lame in both feet, with no claim on the king's favor, prostrates himself, and says, "What is your servant, that you should regard a dead dog like me?"
So says the Christian to the God of the universe... once spiritually dead, totally incapable of anything spiritually pleasing to Him, and yet is lavished with forgiveness according to the riches of His grace in Christ Jesus!
No wonder it's called amazing grace.