As oxygen is necessary but not sufficient for a fire to ignite, so doctrine is necessary but not sufficient to light a fire in our hearts. Without the gracious operation of the Holy Spirit in our hearts, the mere presence of doctrine, even sound doctrine, will leave us cold. God Commands Us to Be Diligent in Study The second positive reason to pursue a knowledge of theology is that God, who is the subject matter of theology, commands us to progress in doctrinal understanding. Let us follow the apostle