In the biography of mashtots, written by a student of mashtots named Koryun, he states a man named Daniel came into possession of a pre-mashtots armenian alphabet which was used to form ("rediscover") the armenian alphabet. https://twitter.com/Bairamian/status/1357095241849913344

Much of the pre-christian literature/music/poems/etc. were destroyed or lost. The start of Armenian Christianity was not Armenian at all. The Bible was written in greek/aramaic and hymns were sung in greek/aramaic also, which the general population couldnt understand.

Efforts to "Armenianize" the religion started in the 5th century. Historians like Khorenatsi proceeded to transcribe pre-christian mythology or in some cases adapted them into Christianity. Shnorhali, for example, infused ancient aspects of Armenian worship into his Arevagal.

During the time of Nerses Shnorhali (12th century) there existed a sect referred to as the Arevordik who called themselves christians but emphasized worship of the sun, described as heretical. They were remnants of earlier sects, notably the Paulican and Tondrakian movements.

Shnorhali believed that these sectarians could be converted, after-all they were Armenians by birth and language. The legend goes that Shnorhali heard these Arevordik singing "heathen songs" during sunrise and it inspired him to compose the introduction of the arevagal.

Legends such as story of Hayk or the daredevils of sassoun see their origins in ancient, pre-christian times but were re-written to include aspects of christianity. Hayk, for example, was made to be a descendant of Noah. Pagan religious practices were christianized.

As for architecture, christianity didnt teach us to build lol. Armenians had mastered the arts of geometry and astronomy thousands of years prior to our conversion. These skills were used to build elaborate buildings and cities.

Because of Armenia's geographic location, it was the location of many wars and with war comes destruction. In the case of our religious buildings, we're told they were constructed over pagan sites and took massive influences from the prechristian architectural style of Armenians.

Our national identity has been consistent for thousands of years before christianity came into the picture. Through time, Armenian religions changed and evolved. I'm not saying christianity is irrelevant but it is not the basis of our national identity.