Most beneficial Buddhist organizations and monastic orders?

My understanding is that, in order to hear the correct dhamma, one must hear it from somebody who displays the outward marks of humility, generosity and selflessness. Otherwise, one cannot be sure one is hearing the correct dhamma. Are there any Buddhist organizations or monastic orders that teach dhamma to lay believers, and do humanitarian work, either in poor countries, or for the general public where they are based? I'm thinking things like refugee resettlement, addiction treatment and recovery, fundraising for medical research or vaccination drives, tutoring special needs children, etc. Can you recommend/provide links for your "favorite" organization? And secondly, is there a "better" or different karma for donating to Buddhist humanitarian work conducted by celibate monks, vs donating to Buddhist humanitarian work conducted by lay followers? Is there a better or different karma for hearing the dhamma taught by celibate monks, vs hearing the dhamma taught by experienced and intelligent lay followers? (Having been raised an evangelical Protestant, I was taught to believe in the "priesthood of believers" and that, for example, bread for communion can be consecrated by any Christian, not by priests only.)