God is always taking us from religion toward Him. Put another way, God is always teaching us that it is not by works but by Grace. It is easy to spot religious effort in cultures other than our own, but often much harder to spot the places within ourselves where we are still doing doing things FOR God rather than In Him. When we replace a true relationship with God with things that we do FOR God, we enter religious spirit.
There are many reason we enter this spirit. Mostly, it enters places in us which still have not fully received His Grace–that He loves us as we are not based on our performance, but on who HE is.
John, the disciple, was able to see Higher because He was close to Jesus, not because He was more spiritual than the others! It is not what we do for Him, but what He is allowed to do in us which really matters in the end.
Other times this spirit enter areas of deep wounding or pain which Jesus has not yet been allowed into. In our time, this spirit is rearing its head more overtly to where it will become clearer what is merely religion and what is actually IN Jesus Christ Himself.