This posting suggests that the Bahai doctrine of 'progressive revelation' does not mean that all previously religions immediately lose their validity and will quickly wither away. It includes some thoughts on the future of Islam and Christianity. "..the new religion functions as a midwife helping the older religions to come through the boundary and reinvent themselves."
Posted on BBST, January 2007
On a non-triumphalist formulation of progressive revelation, which does not suppose that previous religions lose all force and future when a new religion appears, but rather that the old and new both have something to contribute. With a compilation of relevant texts.
Tarikh, 8 October 2006