Catherine Booth preaches about the importance of recognizing and embracing the gifts and calling of women in the ministry, challenging the traditional views that restrict women from public speaking. She highlights examples from the Bible, such as Deborah, Huldah, and Philip's daughters, who were prophetesses and preachers, showing that God has historically used women in leadership roles. Catherine emphasizes the need to follow the guidance of the Holy Spirit in determining one's calling, regardless of gender, and encourages the Church to acknowledge and support the public ministry of women for the advancement of God's kingdom.