The Godmen of India address mamoth gatherings and preach the scriptures and also how to lead and conduct ones life. They could do a lot of good by advising the gathering to plan their families and upermost should be to give them a good education. The merits of a small family and the quality of life could be highlighted. Similarly the Mosques and churches must also join in this effort. I think people may listen and plan their families more out of choice.