Complex sentence: Ching Hai says that each of these five levels are so vastly superior to the preceding one, that whenever someone reaches the next level he or she is immediately convinced that nothing in creation could be greater, and that the ultimate God realization has been achieved.
Split into simpler sentences: Ching Hai says that each of these five levels are vastly superior to the preceding one. Sometimes when someone reaches the top of each level he or she could be in the illusion that nothing in creation could be greater, and that the ultimate God realization has been achieved.