Gatekeepers are people in key positions of influence who can help or hinder the work. Jesus sent his disciples out to proclaim the kingdom of heaven. He told them to enter a house, greet it, and if a man of peace is there (Luke 10:6) to stay there. These men of peace can help clear the way for the gospel to be spread.
Open the gates, that the righteous nation may enter. The one that remains faithful. Isaiah 26:2
Pray that God will reveal the men of peace that He has prepared to open the gates for people to find a right relationship with Him.