Our nature has no power or gifts to produce fear and trust in God...

"It is further taught that since Adam's fall all human beings, who are naturally conceived, are born in sin.  From their mother's wombs they are all filled with evil desire and the inclination toward evil.  By nature, they have no true fear of God and no true faith in God."

As this passage demonstrates, we teach that those who are born according to the fleshly nature have concupiscence.  This means that people not only lack fear and trust in God, but also do not have the power or gifts to produce fear and trust in God.  What fault can be found with this point?  Indeed, we think that we have explained and defended ourselves well enough to good men.  For in this sense the Latin description denies to nature the ability, gifts, and energy to produce fear and trust in God.  In adults, we deny the ability actually to do anything truly good.  So, when we mention concupiscence, we understand not only the acts or fruit, but also the constant inclination of nature.
~BOC, AP, II (I), 2-3