You are God's opportunity in your day. He has waited for ages for a person just like you. If you refuse Him, then God loses His opportunity which He sought through you, and He will never have another, for there will never be another person on the earth just like you.

Bring to God your gift, my brother;
He'll not need to call another,
You will do.
He will add His blessing to it,
And the two of you will do it,
God and you.
--R.E. Neighbour

An oyster on the ocean floor opened wide its shell to let the water pass over it. As the water flushed through, its gills picked out food, sending it to its stomach. Suddenly a large fish nearby stirred up a cloud of sand and silt with a flip of its tail. Sand! Oh, how the oyster disliked sand. It was so rough and made life so unpleasant and uncomfortable and was such a bother whenever any got inside its shell. Quickly the oyster slammed its shell shut, but it was too late. One hard gritty grain of sand had gotten in and lodged itself between his inner flesh and his shell.
My, how that piece of sand bothered the oyster!But almost immediately,special glands God had given him for coating the inside of his shell began working to coat the irritating grain of sand with a lovely smooth and shiny covering. Year after year the oyster added a few more layers of the coating onto the tiny grain of sand until at last, it had produced a beautiful lustrous pearl of great value.
Sometimes the problems we have are a bit like that grain of sand. They bother us and we wonder why we have the irritation and inconvenience they can be. But the grace of God begins to work a wonder with our problems and weaknesses, if we let Him. We become more humble and yielded, more desperate in prayer, closer to the Lord, wiser, and better able to resist the problems. Like blessings in disguise, the Lord soon takes the rough pieces of sand in our life and turns them into precious pearls of strength and power and they become a hope and inspiration to many.
God Bless!