People who call other people bigots need to check they are not bigots themselves.
Intolerance towards those who hold different opinions from oneself:
The state of feeling, or the act of expressing, strong, unreasonable beliefs or opinions.
One way to deal with someone with whom you disagree is to label them a bigot – which they very well may be. However, to do so in an intolerant manner, or by expressing strong, unreasonable beliefs or opinions is to be a bigot.
Avoiding intolerance requires us to first try to understand the opinion we disagree with and at least to agree to disagree without demanding a back-down by the other person, then trying to get on together peacefully and respectfully.
For example, one Christian might believe they should follow the teachings of the Bible, taking it on face value. They might feel strongly that to do otherwise would make them a hypocrite and inconsistent.
Another Christian might read the same Bible and decide to adopt a differing interpretation, disagree with the first Christian and be able to discuss their differing views.
A non-Christian might dismiss the teachings of the Bible altogether and disagree strongly with the Christians altogether.
Are any of these a bigot?
Not if they genuinely seek to understand the views of the others, making sure their own beliefs are reasonable, trying to be reasonable in their understanding of the others then agree to differ but nonetheless live peaceably with each other. This is not easy if opinions are strongly held and if the opinion of one causes the other to feel offended in some way; but exercising tolerance is often an uncomfortable experience.
Of course, if one of these insists that the other must renounce their opinion in favour of their own, then that person is a bigot.