The same reason we eat and drink. Life and death are God's domain, but as He has given us life, He has placed on this planet the resources to sustain it (food and water). He has also given us the resources to heal, and the cognitive power to develop and improve upon methods to use and refine those resources.
Also, as an aside, there have been extremists who have tried to refuse medical science for themselves and their families (including their children), based on their faith in God. They have made the news on occasions when their children have become ill. Most people criticize them for being stupid/ignorant/idiotic/etc. I imagine that you would be in the crowd to crucify the parents for letting their children needlessly suffer. And the reasons for which you would criticize them form part of the answer to your question. |