It normally takes at least 12 years of intensive studies to become a "mujtahid" (who can offer religious guidance). And the title "Sign of God" can't be secured solely by studying: Ayatollahs bestow it on only a few individuals in each generation. The candidate must author a "resaleh" (dissertation), with at least one grand ayatollah publicly acknowledging its theological value.
Traditionally, no man under 40 could pretend to be a "Proof of Islam," for it was at 40 that the Prophet Muhammad was approached by Archangel Gabriel and informed of his divine mission.
But the "Muqtada Project" envisages shortcuts. Sadr is to complete the 12-year course in four or five years, by which time he'd also be 40. Someone could write a resaleh for him and someone else could attest to the work's authority. He could then receive endorsement (tasdiq) from ayatollahs close to the Tehran authorities.
Auf dem kürzesten Weg zum Ayatollah
Wie man einen Nichtsnutz zum Kleriker macht, kann man im FrontPage Magazine nachlesen.