Yahwism
This entire site promotes Yahwism. The present page concerns only the circumstances of its historical rise and continuity.
Yahwism acknowledges the transcendent-personal creator whom ancient Hebrews called "Yahweh", confesses man's defection, and trusts the creator's covenant (his promise of restoration).
Ancient Judaism (the thinking of the tribe of Judah and maybe of other Hebrew tribes) always professed Yahwism but seldom practised it, so that Christ told the Jews of his day, "Your fathers killed all the prophets".
Yahwism's prehistory may (as the Tanakh claims) go back at least to Abraham of Ur in Mesopotamia (1800 BCE), and it may have taken something like coherent form under Moses of Egypt (1300 BCE) or at least under David of Bethlehem (1000 BCE, first Hebrew king in Jerusalem). But Amos of Tekoa (800 BCE) is the earliest known author of a coherent literary expression.
Christianity (in its original form) adds that the promised restoration has appeared in Christ.
As well as being himself the message, Christ was also the first Christian messenger, but his discourses were occasional and he left no writings, leaving Paul of Tarsus to provide the first fairly comprehensive statement, especially in his Epistle to the Romans.
Yahwism, in its Christian form, had some impact around the Mediterranean following its rise, and considerable impact in West Europe from 1500 CE to 1700 CE (the "Reformation" period). Modern thinking has picked up various scraps of it, but as a whole it has never yet prevailed in a large geographical area.