There is the trust which is given to each other by both parts so that different aspects of the whole composing the wedding can be dealt with.
In some aspects, the man would be better at planning and executing; on others, the woman would know better how to deal with provided the man has give. The the necessary support.
Trust, as a leader, the head for the body, means the values under which they stand will never fail their partnership.
That is commitment.
It can only be attained when the couple does not think too high of themselves. Because there is someone higher than any of them and both of them.