Christianity and its effect on self-worth

[Esquilax]

If your assessment is correct, then apparently humans are evil, as from an atheist perspective humans must have invented religion.

Only if you think of religion as this simplistic, instantaneous accretion of ideas, which it isn't. Factually speaking, religions are cumulative; ideas and concepts are added and subtracted and changed within them all the time, and from different people too. They split, and reform, come together and apart, ideas change over time, become lost and sometimes found again, and at no time can the definitive original intent of the movement ever be found.

Humans invented religion, but there's no need to think that they started out with all the evil in them pre-existing. More likely it got added in over time, the same as any other religious concept, as individual evil people or groups added more ideas for their own benefit to the pot. If anything, religion is a testament to how good intentions can become warped, or to the dangers of interpreting select people as the conduits of divine power and bestowing them with an authority that may not be questioned.

In the end, some people are good, and some people are evil. Religions tend to be geared toward authoritarian dictations, and so those smart enough and willing enough to take advantage tend to gravitate toward them, but they aren't the only advocates of religion, nor are the contributions of religion solely negative. Your logic here is not only flawed, it's breathtakingly simplistic.

Yet, OP criticizes Christianity for teaching that people are evil.

Even if your logic actually worked, the best you would be saying is that christianity should be absolved of making a bad situation worse, because the situation was already bad.