People arrive at their moral center from various points, but what defines morality and its sources is amorphous, varying from person to person. Out of all the sources most people consider the basis of morality, the bible is what most people look to.
There are many who believe that a lack of piety signals a deficiency. Many believe morality is connected to a higher power; however many spiritual people commit depraved acts. Humanist work for a better world, different beliefs; same goals.
Humanist believe in their fellow human beings. People can use reason to make just decisions and it is not necessary to worship a diety. For what is not seen may be irrational because definitive proof is needed.
Values begin at different points, but have the same end goal. Lest we forget many proclaim to have strong values, yet commit sins quite frequently.