never wasted

I'm reading a book about Amy Carmichael. It contains a lot of her quotes along with things which had encouraged her but hadn't been written by her. In some places the author is not clear who wrote what, so I'm not sure who wrote this:

God never wastes His servants' pain.
God never wastes His servants' time.
God never wastes His servants' toil.
God never wastes His servants' gifts.

Sometimes I worry that I'm going to waste what God has entrusted me with, especially the things listed in this quote. Yet if I'm fully His and doing my best to listen and live in His will then maybe this is one of the burdens Jesus desires that I lay at His feet. Really, no matter how good I am I can't prevent waste; I'm only human. Once I heard Judy, Isaac's mom, say, "Nothing laid at the feet of Jesus is ever wasted." God help me lay my life and efforts to serve You at Your feet. Help me trust You to keep all of it.