Fair enough--you're not the first Christian to obey the forms without believing the bunkum.
If this is what you mean by religion without belief in God, then it is really nothing more than 'playing along' because you like the culture.
Do you adhere to Christian beliefs besides the existence of God? Do you believe that it is a moral crime to disobey any of the ten commandments?
I like Christmas. I think the ten commandments are adorable and make exquisite door stops. I ALWAYS buy a new dress, hat, gloves and shoes for Easter. I believe I am my brother's keeper. I believe the moneychangers should be driven from the temple (and taxing churches is the best way to that). I believe we do live in a time of false prophets and that all generations have lived in such times. I believe that sometimes it is best to wrestle with our angels and make peace with our demons. I believe that providence has been made, that is to say, we have what we need to sustain us, but we never will so long as we allow Pharaoh to hold grain for the gods while the multitudes starve in Goshen. I believe certain things should be held as sacred, not because god said so, but because we say so. I cry at weddings, namings, and funerals and I think them necessary to mark the passing of our communal lives. I believe that weeping may endure for a night, but joy cometh in the morning.
I believe quite a few things.
Mine is a devotion of Continuous Revelation, Consensual Relationship, Just Community, Social Agency, and Hope.