God as the foundation of liberty and morality
As much as the world may find Christian morality restraining, it is far better than the total moral anarchy that would reign if God did not exist.
If there is no God, then there are no absolute moral standards. An honest atheist will agree that we cannot condemn even most heinous acts of humanity - such as the Holocaust - as absolutely evil because there is no way to "prove" what moral standard is correct. We cannot objectively prove that the Allies’ moral standard is better than the Axis Powers’ standard. We can only prove that the Allies won the war and imposed their morality on the defeated Axis Powers. God is the Primary Source of all morality, and God sits above humanity and whatever "moral standards" we choose to create on our own.
Which God? The God of the Bible, the Old and New Testaments, is the only true God, and His only begotten Son sacrificed Himself for our sins and conquered sin and death. Those who "ask" which god are being intentionally obtuse or deceptive. Everyone knows God exists (Romans 1:20-23), and Psalm 53:1 informs us that those who claim there is no God are fools.
If there is no God, groups of humans can create and agree to certain sets of moral standards - such as prohibiting rape, murder and theft - but these "moral standards" are based on majority rule or state power, not something that can be objectively applied to all mankind throughout the world.
But absolute moral standards are not the only thing missing if God does not exist. The existence of God is the foundation of liberty and human rights, because human beings are made in the image of God. If there is no God that sits above the state, then those in charge of government have unlimited power to do whatever they want. They can plunder, abuse or enslave others and the only real restriction is another army with more and better weapons, better tactics, and more manpower.
The existence of God, then, is a limitation on state power. Scripture tells us in Exodus 21:16 that kidnapping people and selling them into slavery is forbidden. The Sixth Commandment forbids murder, and Genesis 9:6 commands the death penalty for murder. State-sanctioned murder - such as the Holocaust, the Armenian Genocide, or the Rape of Nanking - would be just as harshly condemned as murder by a private citizen and just as worthy of punishment.
As much as the world may find Christian morality restraining, it is far better than the total moral anarchy that would reign if God did not exist. We know from Psalm 14:2-3 and Romans 3:10-12 that no one is righteous. Man's moral depravity knows no limits. It is only reasonable, then, to accept Jesus Christ as your Lord and Savior. This is in gratitude for sitting above the evil of man and for dying for our sins. Sin and death are on one side, while love and life are on the other. Choose life.