I believe in miracles and healing but it is a false belief that in this life everyone will be healed if they have faith. Faith is indeed important. Yet, it is not a mathematical equation in scripture that prayer for healing + faith for healing= healing.
Praise God for when He does heal but sometimes our suffering produces even greater strength in Christ, in us.
Toward the end of the letter Paul shares some hard words with the Corinthians. Mature Christians benefit from correction and conviction. Less mature ones many times don’t.