I guess I never felt like Ueshiba thought aikido was a shortcut, only one of many ways to a goal which many people (the majority of whom are not aikidoists) share. Maybe I am bringing my own bias to my reading of Ueshiba.
In any case, whatever "oneness with God" is, I think one would be hard pressed to show that an aikidoist is more likely to achieve it than anyone else.
One notion that Ellis probably put into my head originally, but seems to jibe with things I vaguely understand about religion in Japan, is that Aikido being a path to oneness with "God" doesn't neccessarily mean it is a path to personal
salvation, but is instead a group or communal activity that creates a storehouse of spiritual goodness. Ueshiba viewed himself as the person to harness this energy and direct it towards the goal of bringing Earth into union with Heaven.
(Though of course I am probably reading too much into that and really Ueshiba was just planning on standing still and feeling the spirals of ki go up and down his body so that he could prevent students from pushing him over.)