First, the Bible has to be interpreted. When someone says they're just doing what the Bible says to do, they didn't greet you with a holy kiss, they're probably wearing two kinds of fabric sewn together, and there's a good chance they don't have tassels sewn on the corners of their garments, all things commanded in the Bible. They don't do those things because they don't believe those commands are binding on them today. And they don't believe that or practice those things because they've interpreted the Bible in a particular way. Or more likely, they've been influenced by someone who told them that is how the Bible is to be interpreted.