This great mystery is about Christ and His Church. It is, therefore, also about Zach and Bekah, who belong to Christ's Bride, the Church. This sign is also for them, His disciples.
Indeed, the two of you are His sign for all of us and all your neighbors.
The world shall neither recognize nor understand this sign; and so the world's "wisdom," counsel and advice for you shall be all wrongheaded. But no matter. Christ shall work His work in you, and He shall manifest His glory in your marriage.
You, for your part, do whatever He tells you.
Rebekah, submit to Zachary in faith. That is what it looks like for you to confess your faith and trust in Christ Jesus, who gives you to this man.
Zachary, love Rebekah in the way that Christ loves her and you and His whole Church. You know that means bearing the Cros and sacrificing yourself for her; not with heroic deeds of valor, but with your whole life, everyday, all the time. It means, in particular, adorning her with the grace, mercy and peace of forgiveness.
Faith and forgiveness. Those are the twin pillars and foundation of your love and marriage in Christ. Not just theoretical or idealistic, and not just for today or this coming week, but in the bump and grind of your everyday life in the world, in body, mind and spirit, till death parts you.
Delight in one another, physically and emotionally; for it is Christ who makes of you one flesh, as well as one heart, one mind and one life (in Him). His Word makes every difference; by it, He sanctifies your union. So delight in one another, not only on your honeymoon, but throughout your life together. For so does Christ delight in His Church, and His Church delights in Him; not only in the head or in the heart, but bodily, in the means of grace.
In that union of heart, mind and body, understand that children are a gift and blessing of the Lord; they are His creation and His good work (not yours). Recognize and receive whatever (and however many) children God may give you as both a sign and a part of the most genuine evangelism and Church Growth. Have babies, have them baptized, and teach them the Word of Christ.
Serve each other, and any children God may give you, with the Word of God. Make of your home a little chapel of the Church by drawing from the wellspring of the Church's life, by availing yourself of the means of grace.
Speak the Word of God to each other. Do it daily, as you here begin your life together with the Word of God and prayer. Zachary, it is your duty, in particular, to serve your wife in that way. It is the most important responsibility that you shall have as a husband, and the most important responsibility that you shall be given, in due time, as a father. Whether or not you ever become a pastor in Christ's Church, you are to be a bishop and a deacon of your household; and, with that, see to it that your family is brought regularly to Christ in His Church.
In this, as in all things, your marriage and your life toegether, your home and family, always point beyond the two of you to Christ and His Bride, the Church. That is true, not only for you and your family, but so also for your neighbors in the world, including those without spouse or children here on earth; not as though to rub it in their face, what they do not have, but to hold before them the promise that is also theirs: that Christ is their heavenly Bridegroom, and that His Church may be their family in Him, both now and forever.
You and your marriage are a sign of that great mystery, of Christ and His Bride, the Church. If you don't realize that, you won't comprehend what marriage is, nor will you understand anything else. It is for the sake of Christ and His Bride, the Church, that God the Lord created all things and established the estate of holy matrimony.
Thus, man (and a husband, in particular) is formed in the Image of Christ Jesus, the incarnate Son, the crucified One. And the woman is made for the man, and brought to him and given to him as a wife, in the image of Christ's Church. For He is the new and greater Adam, from whom His Church is given life, and to whom His Church is given.
It is in the sacred sleep of His sacrificial death upon the Cross that His Eve is taken from His side in the water and the blood; and she is given life by His Spirit in His Word of Holy Absolution.
It is by these means of grace that you belong to His Bride, His Church.
Everything has to do with that Hour of Cross, and nothing else matters apart from that.
Your own resources will run out and run dry. But don't let anyone tell you that it is because of your age or inexperience. It is rather because you are sinful creatures. You have been created by God, not to live by your own reason or strength, but to live by faith in your Creator. Thus, you depend on Him for life and health and every good. Sin has burdened and prevented that faith and life, so that everything is always dying. Even the prettiest girls grow old and get wrinkles. Even the strongest young men grow weary and faint. But Christ has rescued you from sin and death, from the curse and all its consequences.
Your own resources will run dry, but the Cross of Christ supplies all that you need: with and through the forgiveness of all your sins. Nineteen is not too young to know and trust that. Whatever is lacking, He fulfills. Whatever is amiss, He rectifies. Whatever is wrong, He forgives.
For the sake of His Cross, in His great love for you, He provides you with all good things. He feeds you and clothes you, shelters and protects you, and with that you may be content. But He is prone to lavish you with so much more, as He fed the five thousand with a few loaves and fishes, and there were twelve baskets full leftover; and as He made simple water into the best of wines.
With or without the temporal gifts and blessings of this life, you lack nothing, because you are His and He is yours forever. He cleaves to you, as He has made of you one flesh with Himself. That is for keeps, both now and forever. He will never leave you nor forsake you. No, never.
It is in His faithfulness and His forgiveness, free and full, that you live and love each other in faith and forgiveness.
In the Name + of the Father and of the Son and of the Holy Spirit. Amen.