Interact with those whose beliefs are different than yours; to be hospitable, not to try to beat them into submission! We are ALL different - some people chow down on snack-food, while others will only eat locally produced organic produce. Those who drink beer must not look down on those who abstain, as those who refuse bacon must not hold it against those who love it. We are all a little odd; yet God welcomes all of our quirks into the Fellowship of the One.
Who are you that you think you can pass judgement on those who follow someone or something else than you do? Who died and made you God? Each will be measured by how well they followed their own Way - but at the same time, the Lord-of-All will stand with them.
Some determine that one day is holier than another day, but aren't all days meant to be sacred? We will be judged on how well we keep our own holy days sanctified, not how many we force to worship on the "right" day. Observe a day to give thanks to your Lord, and eat (or not) so as to mark the day as being special to you.
We are not alive to serve ourselves; nor do we die for ourselves. Since we live and die for that which we worship, we then belong to who or what we worship.
So, here is what I believe: Christ was born, died, and lived again to confirm that he is the Lord of both - the quick AND the dead.
But, why do you judge your sisters and brothers who believe differently? Why do you hate your brothers and sisters of different beliefs? Though we will all be judged differently, we will all be judged together! Our scripture tells us that all will come to honor the Lord (at some point in each person's life or death, or at some point in the history of humanity?) - so we are not then all equally accountable?