Is it God's "Will" that everyone be healed simply because they asked for healing? Don't you believe God just might have a reason for not healing some, irrespective of their faith?
The greater miracles are those that are done in producing eternal character and fruit.. Salvation, Love, peace, self control, faith etc.
Whatever it takes to obtain these fruits we should value as tribulations and trials and welcome (IF) we are sure they are from God.
i know people whom have weaknesses in alcohol or other drugs.
they are fine if they are walking closely in the Spirit and obedience to God. But when they stray the desire comes and it is a measuring stick to their walking in the flesh.
I have a knee that was injured several times as a young adult. It never got healed after much praying and asking. Years.
then I asked God why not my knee? And I felt He told me it was not healed because of my lack of being a good steward over the foods I eat.
I saw a nutritionist and a sports medicine doctor and given certain foods, supplements and methods to address the knee. I also stopped drinking acid cokes and soft drinks.
after 6 months my weak knee became strong. and through maintenance doses I now do anything i want to on that knee.
i also have glasses for a light prescription. and no healing of this.
Which i feel gives me a physical reminder to keep my eyes on heavenly things as well as stay humble in my flesh.
I would also like to be 6 ft + tall but i remain 5 feet 9 inches.
But one note of sickness or dis-ease or demonically inspired afflictions and I go after them with much prayer and fasting.
And in some cases it has taken years before the person got healed with i.e. crohn's disease.
God has many ways of growing us in faith.
The loving pursuit to pray for a persons health always brings about many benefits.
but in the end i aggressively pursue the thy kingdom come thy will be done on earth as it is in heaven.
For he commands and expects us to pray that principal.
perfect health is in heaven and i believe it is the norm that God desires us to be whole (holy) in our body and soul.
yes we will die someday and our body will fail
but until then I take seriously the scripture that tells us
John 10:10 The thief comes only to steal and kill and destroy; I came that they may have life, and have it abundantly.
both now and in the life to come.