During a wedding I was officiating at, the person doing the first reading from the book of Genesis made a slight error in the pronunciation of one of the words. God was creating a helpmate - a helper. And the helper was to be man's partner. And so husband and wife are to give mutual help and service to each other. They give this help and service to each other through the union of their persons and their actions.
Marriage is a partnership - a sacred partnership.
Partnership seems to demand a mutual respect for the freedom and dignity of the partner. When you choose a partner you don't normally chose someone who is weak. If you are not married and are thinking seriously about getting married, you want to find someone who can be a partner to you. Partnership implies an equality. This does not mean that both people have to be the same, but it does imply that there is present in each of them what they need in order to enter into a partnership.