God is an invention of human beings made to suit their needs, but he doesn't really exist.

All human knowledge begins life as a theory based on intuition and some observations. Theories are invention. When they are checked against reality and for internal consistency we sometimes find that the theory holds tight. Once we become convinced that this theory is correct , we say that we have discovered something real, not that we've invented it.

Instead of saying that God is an invention you should investigate the theory.

OK then. Convince me - why accept Islam!