Endorsed by Chris Williams of Grace to You India; Justin Peters of Justin Peters Ministries, and Phil Johnson, executive director of Grace to You.
In a day and age in which almost all of the prominent female Bible teachers will readily accept and even target male audiences, Susan stands as a breath of fresh air against this increasingly popular, but decidedly unbiblical practice. She is the beautiful embodiment of the Titus 2 woman. 
It is with great and hopeful enthusiasm that I commend this study to you. Read it and take notes. Study. Ponder the depths of what the Apostle John has to say to his readers and ask God’s Holy Spirit to illumine the riches of this epistle to your mind and implant them within your heart. When our knowledge of God is deepened, our love for God is deepened. It is my prayerful expectation that this study into which you are about to embark will deepen your knowledge of our great God and thereby deepen your love for Him resulting in a life of joyful obedience to His commands. Justin Peters—Justin Peters Ministries