When a Christian begins to know Christ as his Lord and Savior, who has redeemed him from death, and is brought into His dominon and heritage, his heart is thorougly permeated by God; then he would like to help everyone attain this blessedness. For he has no greater joy than the treasured knowledge of Christ. So he begins to teach and exhort others, confesses and commends his blessedness before everybody, and sighs and prays that they, too, may come to this grace. He has a restless spirit while enjoying rest supreme, that is, God's grace and peace. Therefore he cannot be quiet or idle but is forever struggling and striving with all his powers as one living only to spread God's honor and praise farther among man, to cause others also to receive this spirit of grace and through it also to help him pray.
What Luther Says - #3014