Can God Choose Not To Perform Miracles?

And when they were come to the multitude, there came to him a certain man, kneeling down to him, and saying, Lord, have mercy on my son: for he is lunatick, and sore vexed: for ofttimes he falleth into the fire, and oft into the water. And I brought him to thy disciples, and they could not cure him.
Then Jesus answered and said, O faithless and perverse generation, how long shall I be with you? how long shall I suffer you? bring him hither to me. And Jesus rebuked the devil; and he departed out of him: and the child was cured from that very hour.
Then came the disciples to Jesus apart, and said, Why could not we cast him out?
And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you. (Matthew 17:14-20 KJV)

I come across this blog on the internet speaking of unbelief.

QUOTE
Imagine you had a successful ministry that saw you healing the sick and casting out demons everywhere you went. Then one day a father brings his son to you, the boy has a seizure right in front of you, and you can't heal him. How would you react? Would you;
(a) conclude that it's not God’s will to heal all the sick?
(b) tell the father that God can heal but He is not going to heal your son right at this moment - maybe in eternity?
(c) speculate that the son has some unconfessed sin in his life?
(d) declare that the boy is healed even though he is still writhing on the ground?
(e) be puzzled?
If you chose (a), then you've built a theology based on your experience that is contrary to the promises of God (Acts 10:38, 1 Peter 2:24). If you chose (b), then you've joined the ranks of those false comforters who say things like, "God used to heal in the Bible, but now He’s on a break." If you chose (c), then you're saying sin can stop the power of God, which it can't – otherwise no sinner could get saved. If you chose (d), the father would think that you're nuts. If you chose (e), then your reaction is the same as the disciples' when they were confronted with this situation.
UNQUOTE

The writer is quite obviously coming from a Charismatic view point. He went on to conclude that the reason why healing miracles do not happen is because of our unbelief.

I do agree that God does heal miraculously, but must He always do that? Can He do it through doctors? Can God choose not to perform miracles? Must God always heal, based on Acts 10:38 and 1 Peter 2:24?

You know of Jesus of Nazareth, how God anointed Him with the Holy Spirit and with power, and how He went about doing good and healing all who were oppressed by the devil, for God was with Him. (Acts 10:38 NASB)

He himself bore our sins in his body on the tree, that we might die to sin and live to righteousness. By his wounds you have been healed. (1 Peter 2:24 ESV)

I read and read Acts 10:38 and 1 Peter 2:24, but I cannot see any support that God must heal, or He must perform miracles. Faith can move mountains, but it is subject to the sovereignty and the will of God.

This is the confidence which we have before Him, that, if we ask anything according to His will, He hears us. (1 John 5:14 NASB)

God can perform miracles, but He is not obliged to perform it on call, like a performer. He is not our servant, He is our Lord. He does not always appear in an awesome earth shattering manner. He does not always heal in a dramatic way.

And he said, Go forth, and stand upon the mount before the Lord. And, behold, the Lord passed by, and a great and strong wind rent the mountains, and brake in pieces the rocks before the Lord; but the Lord was not in the wind: and after the wind an earthquake; but the Lord was not in the earthquake: and after the earthquake a fire; but the Lord was not in the fire: and after the fire a still small voice. (1 Kings 19:11-20 KJV)

Elisha sent a messenger to him, saying, "Go and wash in the Jordan seven times, and your flesh will be restored to you and you will be clean." But Naaman was furious and went away and said, "Behold, I thought, 'He will surely come out to me and stand and call on the name of the Lord his God, and wave his hand over the place and cure the leper.' Are not Abanah and Pharpar, the rivers of Damascus, better than all the waters of Israel? Could I not wash in them and be clean?" So he turned and went away in a rage. Then his servants came near and spoke to him and said, "My father, had the prophet told you to do some great thing, would you not have done it? How much more then, when he says to you, 'Wash, and be clean'?" (2 Kings 5:10-13 NASB)

God is glorified, both in miracles and the mundane.