Hanserd Knollys (1609–91) was a godly pastor/leader and prolific writer among the early Calvinistic Baptists of the seventeenth century. His life and ministry demonstrated a heart for the gospel of Jesus Christ. Despite imprisonment and persecution, he preached the gospel continuously and asked nonbelievers to “open the door” of their hearts to Christ. As for believers, he exhorted them to worship God “in spirit and truth,” live holy lives in both “the form and power of godliness,” and prepare and watch for the imminent second coming of Christ. As his friend Thomas Harrison said, “He was a Preacher out of the Pulpit as well as in it.” It is hoped that this summary of his life and timeless message will spur believers to reach the world with the gospel.