Here’s what it says…
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
What it doesn’t say is that you can’t get fired for an offensive statement. It doesn’t say people can’t use their First Amendment rights to tell you what they think of your offensive statement. And it certainly doesn’t say that people have to respect you at all for making your offensive statement. In fact, the only thing the First Amendment says is that you can’t get tossed in prison for making a offensive statement.
People interested in keeping their jobs, friends, and credibility really should remember that.