Briefly, this provided availability of the teaching and guidance of the Holy Spirit to small children up to the age of decision. Generally, this was considered to be about 8-13 years old, depending on individual maturity and the social mores of the local denomination and the local society. It enables an environment where small children are able to learn what Christianity involves, so they can later choose to be Saved. This continuous, active presence of the Holy Spirit has broad and wonderful consequences. We all see in the news occasionally where someone has recovered from some untreatable, terminal illness.
People sometimes claim all sorts of reasons for such 'cures'.
Sometimes, 'healers' claim credit. We are also regularly aware of a broad variety of phenomena which science cannot explain, and which many Churches try to ignore. Science has always claimed that such individuals cannot repeat such miraculous phenomena under laboratory conditions. The Holy Spirit wouldn't choose to work these miracles under such circumstances. First of all, it would seem demeaning to 'dance' for an audience.