Fundamental meaning and purpose of marriage

Matthew 5:27-32
It was said.... But I tell you that ....
About adultery and Divorce, Jesus more care the motivation and heart of people.
The condition of enter the heaven is according to his behavior and his heart.
An offering to God means nothing if a grudge or grievance is not first put right.
Why?
In Moses' day a wife could be dismissed at whim. His law gave her some security. Jesus goes back to the fundamental meaning and purpose of marriage.
The Bond made when the two become 'one flesh' is indissoluble. Divorce is unthinkable, except where one of the partners has broken the bond already.
How?
Love my wife without any adultery mind. My wife is God's gift to me, and we are one flesh.