Gifts of healings and working of miracles still exist. But as you can see by the responses on this post and others regarding this subject; there is great skepticism, i.e. unbelief. I am not saying "no faith" but "doubt" in a person's heart and mind regarding them being healed; which equals unbelief that God still uses his children to pray for brothers and sisters to enjoy health. It takes the prayers of the righteous interceding for the sick then it is by God's grace and mercy to heal.
And he [Jesus] did not many mighty works there because of their unbelief. Matt. 13:58
The church at Corinthians were mishandling the manifestation of the Spirit. God took three chapters 12,13,14 to go into these spiritual matters and the manifestation and the proper usage - must be pretty important to Him.
As for 1 Corinthians 13:11 When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things.
This is the figure of speech epistrophe - the repetition of a word or words at the end of successive clauses or sentences. This figure of speech used here by God is to place emphasis on "child" - we are all just "children" seeing things unclearly until Jesus comes again, at which point we will be mature [man].
Examples of epistrophe: Lincoln's Gettysburg Address - " . . . the government of the people, by the people, and for the people, shall not perish from the earth." - emphasis on "people".
A Tale of Two Cities - "It was the best of times, it was the worst of times. . . " - emphasis on "times"
Deut. 32:10 He found him in a desert land, and in the waste howling wilderness; he led him about, he instructed him, he kept him as the apple of his eye. - emphasizing God's special care over Jacob
[Information concerning the specific figure of speech epistrophe from Figures of Speech used in the Bible; E.W. Bullinger]