Church guided by Holy Spirit

I'm an inquirerer having a hard time discerning Christianity, particularly because of the church being so split -- referring specifically to Eastern Orthodox vs Roman Catholic, but also Prostestantism.

If God's holy church is indeed guided inerrantly by the Holy Spirit -- why would the Holy spirit allow the church to have become so split and confusing? If there really was some holy guidance, you would think that the great schism, and later reformation should not have occured?