How do you get them to shul? With food, with guilt, with pleas to save the dying or near extinct animal of Judaism. But to ask them to come to shul to commune with the Divine, to find strength and clarity for their life challenges - this doesn't work, because people don't really know if they believe in a G-d or what that word means, because their world views are essentially consumerist-secular, and because they have never had that world view challenged in a systematic and fundamental (not fundamentalist) way.
Then how about getting them to come and connect with each other? Existential isolation and disconect is one of the biggest of the modern sufferings. Well, no, because prayer services as currently constituted do not facilitate the exchange of experience - after all tefila (prayer) is not an encounter/support group, unless we mean encounter with each person's understanding of G-d/HaShem.
It seems to me that shules - temples - synagogues are the perfect place for support groups to be held...one for middle aged dads, one for middle aged moms, one for singles, one for gays, one for adolescents, one for grieving people, one for new parents, one for people wrestling with illness, one for people seeking bliss. Such groups build real communities of meaning, and should precede prayer, the surrendering to the higher power. Indeed I doi not believe authentic prayer is possible without the prior clearing of the inter personal backlogue many of us carry.
Another challenge is communal prayer. Judaism has traditionally valued communal prayer over individual prayer, but communal prayer, humans being social animals, engenders all the pomp, hypocrisy, concern about apperances and role playing that get in the way of an authentic contact. In reform synagogues, where most of the congregants are Jewish ignoramuses who dabble in Judaism to keep a vestigal connection of something to something alive, people bob and bow when they think they're supposed to, look around to check if its ok to sit down now, page through the prayer book desperately trying to find something to read, peer at attractive congregants etc. In ultra orthodox shtiebels people mumble the words like automatons, asleep and numb to themselves and the other, or seek kavod with expressions of piety or their physical location in the shul.