One person believes in eating everything, while the weak person eats only vegetables.
Those who eat must not look down on the ones who don't, and the ones who don't eat must not judge the ones who do, because God has accepted them.
Who are you to judge someone else's servants? They stand or fall before their own Lord (and they will stand, because the Lord has the power to make them stand).
One person considers some days to be more sacred than others, while another person considers all days to be the same. Each person must have their own convictions.
Someone who thinks that a day is sacred, thinks that way for the Lord. Those who eat, eat for the Lord, because they thank God. And those who don't eat, don't eat for the Lord, and they thank the Lord too.