Ironically without a concept of god (or anything similar having ideal quantities) there is no reason neither measure for self improving.

Because what is the end game if not reaching ideal?

Fortunately to have this ideal in your space doesn’t force you to follow any specific dogma.

But i bet finding a branch that fits you best is an easier task than coming up from scratch on your own.

And much more fruitful than finding it among pseudo-atheistic dogmas.