You must take it up on Christian ground, and fight against it with Christian weapons, whilst your feet are shod with the preparation of the gospel of peace
She references the Bible again here. Christian ground = the church? But "feet are shod with the preparation of the gospel of peace" probably means that like boots worn by soldiers, it would deem the wearer safe while going through rough terrain and that the gospel of peace, would provide universal peace for the followers of Christ who wish to tread that path.