What is a man? It could be confusing answering that question because our society is changing quickly on this. Little boys should have their fathers to show them what a man is. They also have other men in their household, family, neighborhood and others like teachers and coaches. And culturally they also are impacted by their favorite athletes, actors and musicians. In some cases, the examples might be good; in other cases, not so much.
Is there a singular standard that describes what a man is and how he should live? Yes. God has provided that standard because He created man.