This principle of unity is the sign of true devotion. Swami reiterates that it is not a celebration for Christians only but is a holy occasion for the entire humanity. It is the desire of Swami that such differences be completely eradicated.

Sri Sathya Sai Speaks, Vol 32 (1999) 

Volunteers of the Sri Sathya Sai Organization celebrate holidays with the underprivileged, underserved and seniors. Swami mentions that the purpose of celebrating holidays is to experience bliss and not merely to partake of delicious food.  This is a fundamental aspect of human values that all members of the organization practice.