Even if the object of desire is an illusory lure, there is a real in this illusion: the object of desire in its' positive nature is vain, but not the place it occupies, the place of the Real, which is why there is more truth in unconditional fidelity to one's desire than in a resigned insight into the vanity of one's striving.- Slavoj Zizek, "Living in the End Times".
There is a parallax shift at work here: from illusion as mere illusion to the real in illusion, from the object which is a metonym/ mask of the Void to the object which stands in for the void. This parallax shift is, in Lacanian, the shift from desire to drive. The key distinction to be maintained here can be exemplified with reference to the (apparent) opposite of religion: intense sexual experience. Eroticization relies on the inversion-into-itself of movement directed at the external goal: the movement itself becomes its own goal. (When instead of simply gently shaking the hand offered to me by the beloved person, I hold onto it and squeeze repeatedly, my activity will be automatically experienced as - welcome or, perhaps, intrusively unwelcome - eroticization: what I do is change the goal oriented activity into an end-in-itself.) Therein resides the difference between the goal and the aim of the drive: say, with regard to the oral drive, its goal may be to eliminate hunger, but its aim is the satisfaction provided by the activity of eating itself (sucking, swallowing). One can imagine the two satisfactions entirely separated: when, in hospital, I am fed intravenously, my hunger is satisfied, but not my oral drive; when, on the contrary, a small child sucks rhythmically on the comforter, the only satisfaction he gets is of that drive. This gap that separates the aim from the goal "eternalizes" the drive, transforming the simple instinctual movement which finds peace and calm when it reaches to a goal (a full stomach, say) into a process which gets caught in its own loop and insists on endlessly repeating itself.
The crucial feature here is to take note of here is that this inversion cannot be formulated in terms of a primordial lack and a series of metonymic objects trying (and ultimately failing) to fill the void.