If we define moral behavior as righteous behavior and not just socially acceptable behavior according to the time we live in then the only point of reference we have for moral behavior is that given to us by the Holy scriptures, namely the Bible. The opponents of this view will point out that we don't need religion to live the golden rule and know to not kill and steal from each other. This may be true but what about the more controversial issues like pornography, same-sex marriage, abortion, premarital sex. The general public consensus on these issues seems to be "If it feels good do it and worry about the future later." Popular opinion is subject to change over time on these issues while Gods word remains unequivocal. The neglect of the counsel of ancient and modern prophets on these issues is bound to have grave consequences for all of society.
In western society, our laws are based upon Judeo-Christian principles, many of which stem from the ten commandments. While it is possible to borrow the principles and forget the source from which they came, to turn from the source is to reject some of the commandments and hence some of morality too.
More often than not, violent and immoral acts are carried out in the name of religion. For example, the so called "War on Terror" was a result of the United States' ignorance of the Islamic faith. Morals are morals, and religious beliefs are based around stories that are unnecessarily true. See that Islamist dude over there? He's gonna kill his religious enemies, because God told him to. Ever heard of the Crusades? Christians were ordered to wipe Muslims off the face of the planet. But there are good things, too. Religious belief isn't all about holy wars... Or is it?
Even though some religious people may feel inclined to be morally good to please their God / gods, morality and religion are not linked. I believe that it actually takes a better person to be moral and not religious, because they are not behaving morally to please their God / gods, they are morally good because they truly believe that's the best way to act. They don't need a deity to tell them how to act, they just believe in being morally good, anyway. Therefore, I don't think being religious results in being morally good and that it's perfectly possible to be atheist and still be morally good.
It is true that religious people often consider their religion's teachings to be the basis of their morality. However, all holy scriptures essentially say the same thing: don't kill people, love everyone, and be generous. These things have been universally accepted as "good". Just because Atheists don't follow the guidance of a particular holy scripture doesn't mean they don't know about the universally accepted ideals of morality!
Typically, when faced with questions like these people will use Christianity as a point of reference. To make this as simple as possible I will as well. From my understanding religion is generally made out to be an open, inviting environment to anyone and everyone. Christianity doesn't appear to be any different. Despite this, the majority of Christians tend to be the opposite: hateful, condemning, and stuck in their own stew of unchanging beliefs. Also, note that these same Christians tend to be white, male, and heterosexual. As everyone (hopefully) noticed, these are the same people in power, in control of the world; therefore they decide what is 'okay' and what's not and society will follow. Even without the religion, they would still be "in charge". Because of this, I believe that religion is an aspect of morals, not the other way around.
Of course not. Just because a person carries the name of a religion does not make them a good person. Every Christian I know is a hypocrite, because it's impossible to follow ever rule in that huge book called the Bible. My mother who says she his a Christian woman curses, drinks, and smokes all the time. Her boyfriend who also says he is Christian has the nerve to threaten to kill my pets because they left paw prints on his motorcycle, stare at teenage girls' butts lustfully even though he is 60, and then try and look like a godly man by saying being gay is against God.
Just the same, having a lack of religion can't make you a bad person either.