[Bear Guy]

Hi Rick, this might be a tall order on a short notice.
As radioman mentioned, there are a number of paths and trails across Bear Island, all of which are not as steep as the church trail from Deep Cove, but all are longer to reach the church. I agree, approaching from the Post Office is unreasonable, but there could be several starting points around the southern end of the island, if you can overcome the lack of any public access. There are John Deere Gators on the island that are capable of navigating many of the paths; the only real 'vehicle' I know of is at Camp Lawrence. I'm sure ISS must have used an ATV of some sort to haul materials to the church for the work they've done. I will say that even with an ATV, this would not be a relaxing ride for a passenger, as the trails are not smooth.
An additional complication was a new sign I found this spring on the Bear Island Forest. It prohibits ATVs; that eliminates wheeled access approaching from the east of the church (for those who follow signs, of course).

The church trail (from docks in Deep Cove) is 1000' long, and rises 150' over that length (though more rise is closer to the shoreline). Much work has been done in the last few years to ease the inclined sections as much as possible, improve footing, and at least one bench added as a rest spot. Maybe just allowing extra time for the elderly guests would ease the trek?