Progressive Revelation

There have been many Messengers from God in humanity's past.

Fact is, all the religious wars have been fought because one set of believers disbelieves in the other set of believers' Messenger.

"My Messenger from God is better, higher, more powerful, and more amazing than what you call a messenger!"

A quick quote attributed to ‘Abdu’l-Bahá:

"Attachment to the lantern is not loving the light."

God will never leave us without a new Messenger, whenever the World grows too Cold from Godlessness...

"Whenever the True Counsellor uttered a word in admonishment, lo, they all denounced Him as a mover of mischief and rejected His claim. How bewildering, how confusing is such behavior!"

Bahá’u’lláh: Gleanings from the Writings of Bahá’u’lláh, Selection CXII, p. 218

"Gracious God! how strange the way of this people! They clamour for guidance, although the standards of Him Who guideth all things are already hoisted. They cleave to the obscure intricacies of knowledge,when He, Who is the Object of all knowledge, shineth as the sun. They see the sun with their own eyes, and yet question that brilliant Orb as to the proof of its light. They behold the vernal showers descending upon them, and yet seek an evidence of that bounty.

"The proof of the sun is the light thereof, which shineth and envelopeth all things."

Bahá’u’lláh: The Kitáb-i-Íqán, paragraph 230, p. 192