Speaking to the Culture of ancient Greece, the Apostle Paul tells the Corinthian Church that it is a shame for men to have long hair. 1 Corinthians 11:13, 14
When Paul was writing to the church at Corinth to answer a series of questions he had mailed to him, the question of "hair" came up. However the actual question was about women's hair, but cutting the hair short in that area was a way for a woman to advertise she was a prostitute. So they asked about hair styles.
Paul writes that he is giving his opinion on the subject, and not giving a commandment from God. He says that he sees a woman cutting her as disgraceful. And a man having long hair as being a "shame." But he also says that if anyone disagrees with that, they can, because "there is no such custom" in the church. Meaning that it is not a commandment or a dogma. Just his own personal opinion.
The Bible has more important things to say than worrying about such irrelevant matters as the way people wear their hair. You think God cares about that?
1 Corinthians 11:14, 15 says: "Does not nature itself teach you that long hair is a dishonor to a man, but if a woman has long hair, it is a glory to her?"