Atheism in future is inevitable for many reasons but on top will be wars and hate among religions.
Christian's, Muslims and branches, Hindus and subs, bodh, jews, communists, all are ready for a show down.
Second is economics as poverty due population on the rise. Masses will not have time for unseen religions and rituals.
Third is globalization and media. It's uniting people of the world.
Fourth is religious clerics who are generally men of straw and mostly con artists. People have started knowing them and a major reason for distancing from religion.