Ever heard the saying "tell me who you walk with, and I'll tell you who you are"? The Bible says something similar: it tells us to leave the company of fools, of people who only drag us down, and to walk in the way of knowledge.
That doesn't mean we should be unkind to anyone, but that we need to carefully choose who influences our thoughts and our attitudes day to day. If you always hang out with people who disrespect others or don't care about anything, it's easy to end up doing the same.
Think of a soccer team: if you train with players who don't put in effort, it becomes hard for you to put in effort too. But if you spend time with people who want to grow, learn, and do what's right, you grow along with them.
Jesus chose His disciples carefully, and called each one of them to leave old things behind and follow Him down a new path, one of learning and growth. When we choose our company well, we get closer to the path God wants for us.
You become like the people you walk alongside.