There are those who choose to live like eunuchs for the sake of the kingdom of heaven. The one who can accept this should accept it

 Matthew 19:1-12

Some Pharisees came to him to test him. They asked, “Is it lawful for a man to divorce his wife for any and every reason?

He replied, “that at the beginning the Creator ‘made them male and female,’ and said, ‘For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh? So they are no longer two, but one flesh. Therefore what God has joined together, let no one separate.

Jesus replied, “Moses permitted you to divorce your wives because your hearts were hard. But it was not this way from the beginning. I tell you that anyone who divorces his wife, except for sexual immorality, and marries another woman commits adultery.”

The disciples said to him, “If this is the situation between a husband and wife, it is better not to marry.” Jesus replied, “Not everyone can accept this word, but only those to whom it has been given. For there are eunuchs who were born that way, and there are eunuchs who have been made eunuchs by others—and there are those who choose to live like eunuchs for the sake of the kingdom of heaven. The one who can accept this should accept it.”

The rabbis disagreed about divorce. Some allowed it for anything that displeased the husband; others only for unfaithfulness. Jesus goes back to God's purpose for man and woman at the very beginning. That is how God meant it to be. Moses, dealing with a situation that fell far short of the ideal, placed a restriction on divorce. Jesus says that adultery is the only legitimate reason.

Why?

Marriage is holy before the Lord join two to one flesh, so original divorce is not acceptable before the Lord, but for the heart of human is hard so Moses permitted them to divorce. 

There is not any and every reason to divorce except because of sexual immorality and marries another woman commits adultery.

The Pharisees came to Jesus and try to find some fault of the law from Jesus. But Jesus is answering the real meaning of the Law. The one who can accept this should accept it. But someone who could not accept it will reject it. It depends on each one's heart.

How?

Be humble and do the right choice, not for my personal opinion but for love and peace.