Proverbs 27:17 (http://bit.ly/2GrREj6) says, “As iron sharpens iron, so one person sharpens another.” We need to surround ourselves with “iron” so that we can be sharpened and we can sharpen others.
In other words, people who are wise, have insight, understanding and knowledge, are strong in character and in their Christian faith, etc. can help us become wiser, stronger, have insight and understanding, etc. Then we can help others in this too.
As friends we help, correct and teach each other, thus, mutually grow. These types of friendships and relationships can help to keep us on the right path.