The almighty and eternal Son of the living God has come down from heaven, in the flesh, to give His Life a ransom for many. He has entered our pagan territory of sin and death, in order to slay and defeat our ancient enemy, that old dragon, the devil or Satan (the accuser). By His death, He has atoned for the sins of the world, reconciled us (all) to God the Father, and thus destroyed death, the sting of death and the power of the devil (which are sin and guilt and accusation). He has plundered the grave and Hades of their dead, and in His Resurrection has opened the gates of heaven to all who believe and are baptized into Him, our dear Lord Jesus Christ.
It is by this precious Gospel, this forgiveness of sins, this life and salvation of His Cross & Resurrection, that Christ establishes, builds, and protects His Church (on earth as it is in the Kingdom of Heaven). Whoever lives and abides within His Church on earth is safe and secure from sin, death, the devil and hell, and shall live and abide forever with Christ in heaven. For He is the Wise Man who has built His House upon the Rock: the winds rage, the rains downpour, the floods rise and pummel that House, but it shall not fall.
Why, then, shall you stand outside and drown and die?
The problem that confronts you, your old Adam and the sinful world in which you live, is that the Wise Man appears to be, not wise, but foolish — and the Rock foundation of His Christian Church appears to be, not solid and secure, but shifting sand.
The Lord Jesus Christ appears to be no more than a man — a great Prophet, perhaps, a good and righteous man, and a powerful preacher, but surely not the Son of God (no one can see that by flesh and blood). And when He is crucified, dead and buried, executed as a criminal, hung upon a cursed tree in naked shame and humiliation, and laid to rest within a borrowed tomb, where is the victory in that? Where is the power and might of His great glory? Where is the promise of His coming? Where do you ever see or feel or experience His Resurrection and His Life?
He says the gates of Hades shall not overpower His Church, but what of the fact that you and your loved ones, your family and friends and fellow Christians, are subject to death and finally buried in the ground? Where is your hope, your life and your salvation? Where is the living God who can and will help you?
The Church appears to be a pitiful fortress indeed, little more than a fisherman’s shack upon the seashore. Its so-called "Rock" foundation is but the Ministry of the Gospel, the preaching of repentance, the spoken word of Absolution, the washing of water with the Word, the administration of bread and wine in the Name and stead of Christ Jesus (the Crucified One!).
And what sort of men are called and sent to preach and administer this Gospel? Sinners, the lot of them! Men like Simon Peter and Paul of Tarsus — a wavering denier of Christ, and a former diehard Pharisee, a persecutor of Jesus. Pastors to this day are quarried from the same rockpile — sinners in need of forgiveness for their own sins — mortals subject to death and the grave, like you — finite, flawed and frail creatures of flesh and blood.
And what keys do they bring? With what do they come to set you free from the death-grip of sin and to open the gates of heaven to you? By what power and authority are they supposed to keep you safe? Nothing but the Gospel, the Word of Christ, the forgiveness of sins, the means of grace. Pitiful and pathetic, it would seem, and impotent in the face of all your needs.
You shall not perceive or believe otherwise, not by your own reason and strength.
You cannot recognize the Lord Jesus Christ for who He is, nor come to Him, nor love and trust in Him, unless the Father reveal Him to you, and give Him to you, and lay Him upon your heart by His Word and Holy Spirit. Yet, all of this, the Father surely does, in grace and mercy and love, by that very Cross of Christ and the preaching of His Gospel, which appear to all the world to be so foolish and miserable and weak.
You cannot open your eyes wide enough to see it, but He opens your eyes in faith by the Light of His Word (by His Gospel of the forgiveness of all your sins). You cannot open your heart or your head to accept it, but He opens your ears to hear, your mind to understand, your heart to believe, and your lips to confess that Jesus is the Christ, the Son of the living God, who has become your Savior, your strength and your song.
The Word that His servants speak in His Name, is His Word. The Sacraments they administer are His works of life and salvation for you. Their forgiveness of your sins is His forgiveness, as valid and certain, even in heaven, as if Christ your dear Lord dealt with you Himself (for so He does in this way).
And this forgiveness of sins, this free and full forgiveness of all your sins, though it seem a still small voice against the rage and roaring of the devil, is a most solid foundation of an impenetrable mighty fortress.
Where sin is forgiven, the devil cannot accuse you, and God’s own Law does not condemn you anymore forever. Where sin is forgiven, death no longer has any claim on you, and must relinquish you (body and soul) unto Christ, your Redeemer, who has purchased you with His own blood. Where sin is forgiven — and your sin is forgiven — there is only life and salvation, come hell or high water against you (it cannot touch you; it shall not reach you). You shall not die, but live; the gates of hell shall not prevail against you (within the Church of Christ); the Word of Christ abides and stands fast forever. His death has been the death of death and hell’s destruction; His Resurrection is your resurrection, and His life everlasting is yours.
In the Name of the Father and of the Son and of the Holy Spirit. Amen.