It is self-evident that certain things are good and other things are not so good.
Morality is not about doing good. In fact, it is about doing certain kinds of good under the pain of retribution.

That is why it is not considered immoral to buy yourself a nice coffee instead of giving the money to the beggar outside the cafe door. It is not good but it is not immoral either.
Morality is about rules and laws. A law is not a law unless a punishment is prescribed for those who break it. The moral person will punish the immoral person by judging and disliking and condemning her or him. If the person has the authority to, he or she can lay down further punishment. For example, the parish priest may fire the housekeeper for being a lesbian.
The law of the land enforces moral rules that affect the people as a whole and claims the right to make any immoral act illegal that it wishes to.
The Christians promote God because they think we need morality. They ask, "Is morality right because God says so?" Or, "Is morality right regardless of whether God agrees with it or not?" Morality is either invented or it is real. If it is invented then you can murder babies for fun. If it is real, it doesn't need a God to make it real. Even he has to obey it. So the Christians say that morality is neither invented by God or independent of him. They say people think they have to choose one or the other not realising there is a third option. They say morality is grounded in his nature because he is by nature kind and loving and fair. They say that being unloving is a sin for it contradicts God's nature. But the third option is denialism. It is in denial of the truth. The truth is that morality is either made up or it is not for it is real. Simple. The third option is a lie for it denies the undeniable. To ground morality on a lie or denial of the truth means you create a system called morality but which is actually not morality but immorality.
Believers in God want to believe in a God who represents moral values and want to argue that he made us as value-honouring persons. They think that we cannot really believe in moral values unless there is a God and these values are grounded in his nature.
Suppose I need to believe in a good God in order to explain why I have values. I am really grounding this in my belief in God and not in God. Trusting my belief in God is not trusting in God. It only superficially looks like it. So I am still treating my values as brute facts and trying to get away from that.
My values are often called moral values by Christians. But just because I want to see babies safe from attackers does not mean this is a moral value. Good and moral are related but are not the same thing. Good is about what benefits. Moral is saying that good must be done under the threat of punishment. Moral is a kind of social law. If I need belief in God before I can see that a baby must be protected from suffering then I am an evil person who needs the belief to rein in my evil. But restrained or not its still there inside festering away.
Religion says we have a duty of obedience to God to become good people. Duty is based on the idea of owing. If I owe you money and you have no punishment for me, not even punishment for me in the form of disapproval, if I refuse to pay, then it follows I do not owe it to you at all anymore. If you say I do, you have no right to be taken seriously. By not making it a rule that you get paid, you are effectively saying you are not owed the money anymore. A rule with no price demanded of those who break it, is not a rule. Christians claim that they can sin and as long as they confess and get forgiven promptly they will be fine. This is really admitting that they do not have a duty to do good but only a duty to get forgiveness for their sins. That is a travesty of right and wrong. Its a mockery of those who suffer.

Murder is the unlawful killing of a human being. The doctrine that an all-good God has the right to kill makes us see death as less bad than we could which is a help to the person contemplating committing a murder. There is no need to believe in God therefore belief in God is encouraging murder.

It is obvious there is no real match, only a superficial match, between our values and the alleged values God has.