Here’s where we have to go past game mechanics to role-playing: The cleric has allegiance to a higher authority, and can appeal to this authority. Often our hero will have a compatriot who doesn’t break as many rules and remains tied in to high-ranking government officials. This compatriot can intercede with the higher powers, and obtain favors that not even a techie mage can obtain. The techie mage can get you an access card to get into the building under a fake name (good until you are discovered) but the intermediary can get your name on the good list so you are able to enter under your own name and requisition things. The techie mage can get you into databases, but the intermediary can call in the cavalry (or, in religious terms, summon avenging angels to fight beside you). If your wounds are worse than any field medic can treat, the intermediary can get you officially recognized as a good guy so you can go to the hospital in an ambulance rather than a squad car (i.e. cast “raise dead”). And, ultimately, the friend who’s still in good graces can give you the most divine gift of all: Official forgiveness for your sins.As I note in his comment thread, the etymology of cleric points us to the modern-day counterpart, the intervening figure who intercedes with the higher powers and obtains their forgiveness -- or, in the case of an evil character, summons them against the forces of Light.
The lawyer, of course. I feel better about my job already. (Though I'm pretty sure I've never had a cleric PC in my life ... maybe a magic-user/cleric once, briefly?)