Surely, we receive much more of God than we can ever expect to obtain from emperors, or any temporal authorities. If we do not believe that there is a future life, why then, of course, we need no other helpers than rulers, parents, or physicians, whose duty is to see to our temporal welfare. But if we believe that there is a life after this is ended, then, beyond all doubt, we need this our Savior. Neither king, nor father, nor mother, nor physician, nor any one else, yea. not even an angel, can give us that life. It is true, our Lord Jesus will also be with His people in the troubles of this life, and will assist them in their temporal distress, even if kings and parents and friends fail, or are not able to assist. Yet this is not His chief nor highest office; hence we do not preach of it especially.
His special office is to save from sin, from eternal death and the dominion of the devil; hence He proclaims His name Jesus, to be known by all sinners, for they need a Savior. If there were no hell, no dominion of the devil, no eternal punishment or torment, men might live without Jesus the Lord; for then when one dies all would be at an end, as it is with a tree when it falls, or with a cow when she dies. Hence those who do not believe in God nor in a future life, become a wild, licentious brood. But he who believes in a God will immediately conclude that not all is ended with the close of this life, but there is, beyond this, another life, which is everlasting. That God does not principally concern Himself about the present life of man is evident from the fact that He permits so many wicked scoundrels to live, and to flourish here upon earth. But He has promised us an eternal life hereafter, and the Child Jesus came to be our Savior and our Guide to this future existence. If He brings us into that life, then has He assisted us indeed, no matter what trials we may in the meanwhile be called to endure here upon earth; yea, though they be so severe that it might seem as if God had forsaken us, it matters not, since we know that He saves unto eternal life. This must satisfy us, let the world wag as it will.
(Luther’s House Postil, Sermon for the 2nd Sermon for New Year, Volume 1, p. 143)