Perhaps many of us (nontheists) are just sick and tired of repeating the basics - social contract (Hobbes), golden rule (Jesus, among many others), and categorical imperative (Kant). These are all powerful bases for a system of ethics and morals that do not require belief in the supernatural, or some peculiar notion of rewards and punishments after death. Only the beginning, of course, but three minutes of checking into those concepts will give you the general outline, Texas Roofer.
As to who I’d rather found my wallet, I would be happy if either a ‘devout’ (presumably meaning they follow the Church’s teachings, not just say lots of rosaries and stuff) Catholic did so, or an ethical nontheist. If someone’s a jerk, it doesn’t matter to me if they’re religious or not, and likewise, if someone’s really thoughtful and upstanding, again, their religion or lack thereof doesn’t concern me. I recommend those three basic ethical principles I mentioned for theists as well!
I do use the term ‘nontheist’ since ‘atheist’ isn’t precise, in a way. Many, if not most, nontheists, do not categorically deny the existence of the supernatural, so much as we find the entire question of whether such things
might exist to be rather pointless in the absence of any evidence either way. As in ‘we don’t Believe, in the existence or non-existence of deities, period.’ And that’s really the only generality one can make about nontheists (or atheists if you insist on using the term…I’d be careful with it though, since that leads to misconceptions), the same way one cannot make general statements about all theists (or religious people, but again, that can get imprecise) except that they
do believe in the supernatural.
Just trying to be helpful!