Actually the argument comes before this... It is that we only know the right thing because of God... If not for God then what is right or wrong is debateable e.g. morally relative and situationally derived... Punishment, Hell or consequence is a result of doing bad...
SO -doing the right thing first and foremost requires knowing the right thing to do...
Interesting. This is a common form of argument against evolution, though it rests on several fallacies that have doubtless been pointed out to you before, and will be pointed out to you again.
I am intrigued however. What if you had a crisis and lost your faith. (Perhaps imagine a hypothetical situation where you become appalled by the repeated lies of those who profess to be Christian ;) ). Would you teach your children different morals under such circumstances? Would you behave differently (from a moral point of view)?