Why do people claim that God gives morals a foundation?

Of course you dont need to read the bible to figure out that hitting someone in the face hurts them and is not nice. The whole reality is that everything good comes of God and everything bad comes from Satan, two complete opposites that take on so many forms in society. So as much as atheists do not like this concept when they help their neighbor move in for the first time with good intentions to welcome them then they are in fact serving their fellow man and also serving God. When you give someone good advice on a career with intentions to motivate and help another you are serving your fellow man and also serving God. Every good moral thing comes from God whether they accept it or not