The idea that blood and organ donation is wrong has its origins from pagan and cult systems. Some Christians are afraid that if you donate your organ like eye, in resurrection you will not have that organ. This is absurd. The Bible says that if you are saved, even if your physical body is burnt or damaged, you will be in heaven and have new resurrected bodies. No human being can harm a believer's soul.
28 And fear not them which kill the body, but are not able to kill the soul: but rather fear him which is able to destroy both soul and body in hell.
Some cults like "Jehova Witnesses" have spread false messages that Jesus cleanses the physical blood of human beings and so it shouldn't be transferred. These are neither logical nor biblical. The Bible commands us to even give our entire body and life for the sake of others, driven by the love of Christ.
Our present physical body will decay anyway. There is nothing wrong in donating organs.
The Bible urges us to "do good to all men". When unbelievers who do not have the Holy Spirit indwelling in them are gladly donating organs and blood, how much more good works should we who have tasted the love of Christ do?
Please donate blood to others when you could, as an act of demonstrating God's kindness. As a believer, any service you do for God's sake will be rewarded in heaven.