The Merriam-Webster Dictionary says:
noun \ˈtä-lə-rən(t)s, ˈtäl-rən(t)s\
: willingness to accept feelings, habits, or beliefs that are different from your own
: the ability to accept, experience, or survive something harmful or unpleasant
This definition implies that tolerance means bearing with, or accepting, things one dislikes. I first learned the word as a small child, when my physical and occupational therapists exhorted me to tolerate my leg braces, hand splints and exercises meant to decrease the severity of my Cerebral Palsy. I understood, even as a five-year-old, that they didn't expect me to like my braces, splints and exercises (indeed, I hated them with a passion), but they certainly expected me to accept them.
Lately, theological and political liberals seem to equate tolerance with approval. My conversation partner on Twitter, for instance, views my opposition to same sex marriage as a denial of his rights. But I accept the fact that same sex marriage is legal in Massachusetts, and will soon be legal in all 50 states. I believe its legalization will ultimately impinge on religious liberties (and perhaps I'll cite examples in future blog posts), but I tolerate the fact that same sex marriage is the law of the land.
My conversation partner, conversely, has forbidden me from basing my arguments against same sex marriage on my Christian beliefs. That being the case, he demonstrates intolerance toward Christianity. I don't hold illusions that my reasons for opposing same sex marriage could persuade him to adopt my point of view. But since he demanded to know why I take the position I do, I wish he'd tolerate my replies.