Ismaili philosophers actually affirm that yes Christians should revere the cross and Muslims should revere the Shahada, because outwardly, these symbols are different, but inwardly there is a unity.
If there’s anything we can take away from these Shi’i Ismaili Muslim perspective … is that, while religion may have outward theological differences, these outward theological differences may be reconciled at the level of deeper esoteric meaning. And thus, outward diversity may in fact simply be a symbol of inward unity.
http://www.youtube.com/watch?v=r2Hy1j7-zCE
