You literally owe your existence to them, if for no other reason than that you owe a life debt to them. Beyond this however typical parents teach their children to speak, the customs of their people, the difference between right and wrong, how to express themselves, etc. Your parents are your 1st, last and most important teachers and mentors (and this applies no less to adoptive parents, if anything they deserve more respect for choosing you). Not all parents foster loving (or emotional at all) relationships but you don't have to like someone to respect them and to fail to realize this is a most impious failing for any child.
As always, I ask that any atheists that wish to comment limit themselves to the philosophical aspects of the Maxims as I don't want these threads derailed into a general theological debate.
As always, I ask that any atheists that wish to comment limit themselves to the philosophical aspects of the Maxims as I don't want these threads derailed into a general theological debate.