It seems reasonable to me to expect that people who love and follow the Lord would be happier and better people than those who don't. If God was real, and His laws were real, and His lessons were real, and faith in Him manifested changes, and prayer to Him worked, and His love was powerful, then how could His people not enjoy better lives and be better people? If His intervention was not a factor then simply their living a life in sacred resonance with a universe He made and they better understood would seem to guarantee some improvement.
And yet, I can find no significant evidence of this. I've known bad people of every faith (and lack therein). I've known unhappy people of every faith (and lack therein). All I've noticed is that the happiest and best people seem to be those who question and explore their religious beliefs (whether they believe or not). I certainly can't argue that the atheists or agnostics might be barred from entering heaven upon their death, but here on this good Earth God seems to show them no particular disfavor in the form of excess misery, death, poverty, etc. This lack of a strong difference between the lives lived, in or out of accordance with His wishes, does not encourage me to believe.