What does, "My wife is the very brick and mortar of the church" mean in The Crucible?
In The Crucible, Francis Nurse is describing his wife, Rebecca, and her importance to him, his family, and the community. She is metaphorically the foundation of the family and his love. She is also the mother of his seven children, and like a lot of women, the one who probably manages the household and keeps it running. They have been married a long time, and it is a secure marriage built on the “bricks and mortar” of love and trust. Rebecca Nurse is also, to use another building metaphor, a pillar of the community. She is a religious church goer and supporter of the Puritan values of the community. She is also a midwife, a necessity to have around for the Puritan society that wants to grow and establish a community in the new world. She is respected and looked up to as a woman of morals. She is metaphorically the foundation of a marriage as well as the stability the Puritan society needs to build their religion. Unfortunately, Rebecca Nurse is accused of witchcraft by Mrs. Putnam because of Mrs. Putnam’s jealousy. Mrs. Putnam had several children die in infancy, and Rebecca Nurse was the attending midwife.
This line is spoken by Francis Nurse about his wife, Rebecca, as a way of defending her against charges of witchcraft.
The line is a metaphor meant to emphasize how important she is to the church.
If you think about an actual church builiding (especially in those days), it's made of brick and mortar. Those are the things that form the walls of the church and make the church what it is.
So what he's saying about his wife is that she is (figuratively only), as important to the church as its bricks and mortar. He's saying that she is what holds the church up and makes it what it is.