Why doesn't God do miracles like restore limbs or legs? Why not do something that clearly must be God and God alone?
We must understand that much of this question is an argument from silence. We don't know that God never regenerated a limb or for that matter fixed a fender. We have very few miracles recorded in the Bible when one takes for granted that it was written over about 1500 years give or take a few centuries based on various theories.
Who can really say what God has done or not done regarding miracles since our history of them is so incomplete. Miracles are rare by definition. One could argue that the healing of leprosy may have restored some limbs since leprosy often leads to a loss of toes, or fingers (2 Kings 5:14; Luke 5:12; ) and so these may have been restored. One can look to the book by Eric Metaxas for a modern defense of miracles and stories that witness of them happening in New York City.
Now the real question is why does God not produce more miracles in order to convince people of the truth of the divine existence? It would appear that the most miracles occurred during the ministry of Jesus the Messiah. But this great demonstration of power did not produce a great turning towards him in the long run. The Messiah Jesus seems to lack faith in the idea that people who are looking for more miracles are looking for a relationship with God.
"But He answered and said to them, "An evil and adulterous generation craves for a sign; and yet no sign will be given to it but the sign of Jonah the prophet;" Matthew 12:39
The apostle John tells us that:
"He came to His own, and those who were His own did not receive Him." John 1:11
So the person that produced the most miracles in biblical history was rejected and crucified and only had about 120 people who were responding in true faith. Some of the 500 doubted even seeing Jesus the Messiah raised from the dead.
I think that the problem is we are assuming that we want to be honest with the evidence they have about God. It appears that humanity lacks objectivity when it comes to the issue of God. We are not seekers after the reality of the divine existence. We don't mind making "god" in our image, but we are not so open to accepting the Creator for who the divine person really is in reality.
"For even though they knew God, they did not honor Him as God or give thanks, but they became futile in their speculations, and their foolish heart was darkened." Romans 1:21
I have responded to the options of this lack of evidence for God recently due to a similar question raised at Socrates.See - http://
Let us assume for the moment that there is a Good God who would want human beings to respond to the divine person in a positive way. If we assume this then we would also have to assume that the only reason there were not more miracles and greater concrete evidence of God's existence is that God knows that humanity would only become more morally guilty with such a revelation since they would not respond to it by loving God with all their hearts, minds, souls, and strength. The more revelation the more responsibility. A merciful God would limit revelation to those who are not going to respond to it well.
God providing concrete evidence of the divine existence seems tied to a heart desire to seek a relationship with God.
"And without faith it is impossible to please Him, for he who comes to God must believe that He is and that He is a rewarder of those who seek Him." Hebrews 11:6
Faith here is justified true belief based upon the evidence that is given in creation and the human psyche (Romans 1:18-20)
It can also be argued that there is enough evidence for knowledge of God but a lack of objectivity towards this evidence.
Now another problem could be that such an approach would also cause a loss of something that God is hoping to develop with humanity.
This possibility has been explored by some of the existential philosophers. Here is an example.
The King and the Maiden
"Suppose there was a king who loved a humble maiden. The king was like no other king. Every statesman trembled before his power. No one dared breathe a word against him, for he had the strength to crush all opponents.
And yet this mighty king was melted by love for a humble maiden who lived in a poor village in his kingdom. How could he declare his love for her? In an odd sort of way, his kingliness tied his hands. If he brought her to the palace and crowned her head with jewels and clothed her body in royal robes, she would surely not resist-no one dared resist him. But would she love him?
She would say she loved him, of course, but would she truly? Or would she live with him in fear, nursing a private grief for the life she had left behind? Would she be happy at his side? How could he know for sure? If he rode to her forest cottage in his royal carriage, with an armed escort waving bright banners, that too would overwhelm her. He did not want a cringing subject. He wanted a lover, an equal. He wanted her to forget that he was a king and she a humble maiden and to let shared love cross the gulf between them. For it is only in love that the unequal can be made equal.
The king convinced he could not elevate the maiden without crushing her freedom, resolved to descend to her. Clothed as a beggar, he approached her cottage with a worn cloak fluttering loose about him. This was not just a disguise – the king took on a totally new identity – He had renounced his throne to declare his love and to win hers."
So what we have here is that on the one hand the question assumes the objectivity, intellectual honesty, and goodness of human beings who are only suffering for lack of knowledge about God due to God lacking character or competence. Yet, in cases where great evidence was given such as in the ministry of Messiah Jesus (it should be noted that even those opposed to Jesus record he was a worker of miracles - http://coldcasechristianity.
So we have to doubt either the competence and character of humanity in dealing with truth or the competence and character of God in providing evidence. Somehow we find it easier to doubt the competence and character of God than our own.
So are there rational responses to this argument. Yes, for there is some evidence for God's existence which many find sufficient and God may know that providing more evidence would not lead to greater faith but greater guilt and/or miss the mark of the type of relationship God wants with humanity. The faith that God wants is not some mere formal intellectual faith but a loving trust.
Those are my musings. God told us that "East of Eden" the world would be hard and filled with thorns, sickness, struggles, pain, tribulations, and death. Our humanity would rather live apart from God's kingdom in perfection and has chosen "East of Eden" where we can be free of God's rule and healing presence. This perspective has little faith in our competence or character. But perhaps that is where the problem rests.