The pastor can say what he pleases, but in a NON theocratic nation marriage is simply a contract between people
for agreed upon duties & how you're going to treat one another, financial obligations, etc...

If he's trying to convert people to the Abrahamic faith, he's going about it the wrong way. Besides Jesus
ate with "sinners", didn't judge anyone, & people should remember the parable of The Good Samaritan too.
It's not how pious you are, but how you treat your fellow man, that's what's most important in this life.