Re: celebrating christmas
acknowledging each others' holidays with a genuine well wishing attitude is a reward in itself, because which ever faith one believes in, is represented by that simple action of rejoicing and humility in partaking and sharing a good feeling of festivity.
it will not make anyone lesser in being from their own faith.
thanking the higher being, being around close friends and family, especially being charitable and giving to deserving poor and indigent people, is a good effect that the spirit of religious holidays cause in good people to engage in selfless acts of kindness and feel connected to as good friendly people, with each other.