The good tidbits are there. The bad was always there. Even early christians thought so.

Before the religion organized into a hierarchical orthodoxy, communities distant from the emerging establishment (not particularly attached to jewish traditions) in places like Alexandria were left to their own devices to figure out christianity: they formed loose households & study circles to interpret texts in the context of their own traditions & culture, and they drew their own conclusions.

• Reading the older jewish scriptures & newer texts quite literally, they concluded there were 2 deities. 1 of whom, the unhidden Demiurge (Yahweh of the old testament) who had created the material universe, was a vengeful and ignorant deity inimical to human welfare. Consequently, material existence is flawed & evil, and they must escape that realm by seeking personal knowledge of the other, hidden deity: the transcendent spiritual entity, the Silent Depth (or the Monad), who briefly inhabited Jesus with that revelatory wisdom or logos found in the newer texts. In other words, there's cool god (Jesus's god) & evil genocidal god (Yahweh).
• Moreover, they concluded that church authority isn't needed: Jesus had awoken a spark of divinity in matter that would find its way back to its transcendent source with little need of episcopal authority or sacramental practice.

This interpretation became known as gnosticism.

Sticklers with the evil trash god of older jewish scriptures didn't like this idea, became early church authorities, denounced it as heresy, & purged all the texts they could of it. Nonetheless, early christians thought there was bad in those texts & tried to handle it.