Keep a good conscience
As God's children we strive to keep the good conscience we have received through faith in Christ. It is not always easy to maintain a good conscience. The world is deceitful and we are weak. For this reason the Savior gives us this advice: "Behold I send you out as sheep in the midst of wolves; therefore be shrewd as serpents and innocent as doves" (Matt. 10:16). These words speak about keeping a good conscience in the midst of the deceitful world.
Dr. Luther speaking about this topic says: "It is shrewd teaching and living, if there is no flaw in our conscience when the world and the wolves condemn us and kill us. - Being innocent is teaching and living without a desire for glory or revenge regardless of what people are like, good or bad."
The world seeks to deprive us of a good conscience. First the world tries to get us to fall into sin so that we ourselves will feel that we have lost our good conscience. The other way is more subtle: The world tries to turn us away from God's Word and Commandments by trying to convince us that it is wise to act differently.
In warning us the Savior urges us to be shrewd but to be innocent at the same time. He wants to say: Do not be naive in relation to the world, but be wise. Know where the world is trying to lead you. The world tries to make the innocent guilty in order to cover its own faults. Watch, "beware of men".
But perhaps you ask: Who is wise enough to understand all the wiles of the unbelieving world? We all lack wisdom. For this reason our Savior offers us another word of warning: "Be innocent." When we cling to God's Word and do not engage in scheming, strife or evil, we will be safe.
The exhortation of Jesus, "Be as shrewd as serpents", has often been used in the wrong way. It has been used to defend some sin of neglect, or some activity in the church that is contrary to God's Word. But Jesus' exhortation does not offer support for a defense of sin, for in defending sin innocence is lost. The Apostle Paul writes: "For our proud confidence is this, the testimony of our conscience that in holiness and godly sincerity, not in fleshly wisdom but in the grace of God, we have conducted ourselves in the world, and especially toward you" (2 Cor. 1:12). There is a difference between fleshly wisdom and that wisdom, which when used, permits innocence to survive.
Therefore let us strive with fear and trembling and remember that we have been redeemed with the precious blood of Christ. Our conscience has been cleansed with His blood, and we can cleanse it each day with God's grace. Christ absolves the penitent sinner and grants him the joy of salvation.