I'd first like to establish my premises before forming my question.
1) The Christian God is the one true god.
2) God is omnipotent, omniscient, and possibly omnibenevolent (though this can be debated.
3) God has personally interceded in human history and human lives in the form of miracles.
4) God continues to intercede in human lives today in the form of miracles.
5) These miracles include, but are not limited to, healing the sick, protecting people from fatal accidents, healing the crippled, and healing the deaf and blind.
6) God has not in modern times healed an amputee.
The question: Why does God not heal amputees? Some possible answers and rebuttals:
1) God can not heal amputees. But isn't God omnipotent?
2) God only heals wounds that are fatal.But blindness or deafness aren't fatal, and God supposedly heals those.
3) God has some seemingly irrational grudge against amputees. This seems to contradict his omnibelevolence.
4) God does not perform miracles that contradict natural law.
A) Why did God choose to set down natural law in such a way that healing cripples is a contradiction?
B) Is God then limited to act in ways that conform to natural law? Doesn't that limitation restrict his omnipotence?
C) Many historical miracles contradict natural law.
5) Healing amputees is an extreme miracle, and God no longer performs extreme miracles because they would confirm his existence rationally, and he wants people to come to him through faith.
A) In the Bible and well into the medieval period, God seems perfectly fine using his miracles as proof of his existence.
B) If that's true, then shouldn't people stop using miracles to argue for God's existence?
C) If that's true, then what is the point of miracles? Are they just rewards for the faithful?
6) Amputees do not have enough faith to warrant God's intercession.
A) Why does healing amputation require more faith than bringing the dead back to life?
B) Why don't they have enough faith? Are all amputees incidentally faithless people, or is faith stored in your extremities?
7) In the future we will be able to regrow limbs, so God's miracle is making that medical technology possible.
A) God made cancer treatment possible, but that doesn't stop people from claiming that God healed them without them undergoing treatment.
B) God historically performed miracles that weren't medically possible at the time, so why is amputation different?
8) Ours is not to reason why.