We all admire the courage of the Apostles who witnessed for Christ before the Council that had called for Jesus' crucifixion. To prepare ourselves to make a faithful witness we would do well the study daily the catechism because it expresses the right understanding of the Holy Bible.
For God's sake I beg such lazy bellies [pastors] or arrogant saints to be persuaded and believe that they are truly, truly not so learned as they imagine! They should never assume that they have finished learning the parts of the catechism, even though they think that they know it ever so well. There are many benefits and fruits to be gained, if it is daily read and practiced in thought and speech. For example, the Holy Spirit is present in such reading, and meditation. He bestows new light and devoutness. In this way the catechism is daily loved and appreciated better.
Besides, catechism study is a most effective help against the devil, the world, the flesh, and all evil thoughts. It helps to be occupied with God's Word, to speak it, and meditate on it, just as the first Psalm declares people blessed who meditate on God's Law day and night (Psalm 1:2), from which the devil runs and may be driven away. You will not release a stronger repellant against the devil.
Now, for this reason alone, you ought gladly to read, speak, think, and use these things, even if you had no other profit and fruit from them than driving away the devil and evil thoughts by doing so. He cannot hear or endure God's Word. God's Word is not like some other silly babbling. Paul says in Romans 1:16, it is "the power of God." It is the power of God that gives the devil burning pain and strengthens, and helps us beyond measure. (paragraphs 9-11)
Condensed from CONCORDIA: THE LUTHERAN CONFESSIONS, copyright 2005,2006 by Concordia Publishing House. Used by permission. All rights reserved. To purchase a copy of CONCORDIA, call 800-325-3040.