"Standing in the gap" means to intervene on behalf of others, often through prayer or at times action, to protect them from harm or to bridge a divide.
The phrase "stand in the gap" originates from the Bible, specifically the Book of Ezekiel. It refers to a person who acts as an intercessor or mediator to protect others from harm or destruction, either by repairing a literal wall or by making a spiritual defense through prayer. Christians are called to "stand in the gap" for others in their communities and the world by praying, acting, and interceding on their behalf.