Do you feel that, because of your sins, you cannot go to the Lord’s Supper?
Perhaps you do because of how many your sins are. Or perhaps because of one that is besetting, a sin that many times you have resolved and even taken measure against repeating, but here you are again, right in the same sin. Perhaps it is because of a line you crossed from prior sins to this new one, this worse one, as if sin has so overgrown the garden that there are no fruits of faith left in it. Perhaps it is because you compare yourself to others who seem to not even know anything about the existence of the kind of sin that grips you. Them make life seem so easy, as if they are not even tempted, but casually walk in the holiness you desire.
If this is you, then hear and believe the Word of the Gospel:
Come to me, all who labor and are heavy laden, and I will give you rest. Take my yoke upon you, and learn from me, for I am gentle and lowly in heart, and you will find rest for your souls. For my yoke is easy, and my burden is light. (Matthew 11:28-30)
Luther uses this Word as motivation to move people to come to the Sacrament.
Because of your distress, this command, invitation, and promise are given to you. This ought to move you. . . . He means those who are weary and heavy laden with their sins, with the fear of death, temptations of the flesh, and of the devil. If, therefore, you are heavy laden and feel your weakness, then go joyfully to the Sacrament and receive refreshment, comfort, and strength Mathew 11:28.
This teaching also is given in the article on “The Holy Supper” in the Formula of Concord:
Some Christians have a weak faith and are shy, troubled, and heartily terrified because of the great number of their sins. They think that in their great impurity they are not worthy of this precious treasure and Christ’s benefits. They fell their weakness of faith and lament it, and from their hearts desire that they may serve God with stronger, more joyful faith and pure obedience. These are the truly worthy guests, for whom this highly venerable Sacrament has been especially instituted and appointed. For Christ says: Come to Me, all who labor and are heavy laden, and I will give you rest. (Matthew 11:28).
 Martin Luther, Large Catechism, Part V, The Sacrament of the Altar, Paul Timothy McCain, Ed., Concordia: The Lutheran Confessions, 2nd ed. (St. Louis: Concordia Publishing House, 2006), 439; LC V.71-72.
 Solid Declaration of the Formula of Concord, Paul Timothy McCain, Ed., Concordia: The Lutheran Confessions, 2nd ed. (St. Louis: Concordia Publishing House, 2006), 573-574; SD VII.69-70