Talk is cheap. "Lifting up [person X] to the Lord" type prayers is an insult from individuals who have healthy bodies but refuse to donate blood. If you believe Christ bled for you - are you willing to take up a slim fraction of that burden and endure 15 minutes of discomfort to save the life of a fellow human?
Me, I hate needles. HATE the little buggers. Hate the sight of them, hate the feeling of cold steel sliding into my arms, hate the smell of the antiseptics swabs used beforehand. No matter. I gave blood today. Carved bruised crescents into my palms from my fingernails as they drew out my blood, but I did it. But if that 15 minutes of discomfort can buy somebody in a coma another 15 hours to fight for his life, it is well worth it. And as soon as I'm allowed to return, I'll be back, sleeves rolled, to get tapped for another pint.
I don't know about God - but I haven't heard any reports of blood units being multiplied like bread and fish.
The gift of life is a phone call and a car ride away. Prayer can wait.