What is the second type of eating in the sacrament that Lutherans confess? I don't understand how there are "two" types of eating.
Questions regarding what Lutherans confess will lead to answers from the Lutheran Confessions. The following is from the Formula of Concord. Thorough Declaration. VII. Of the Holy Supper.
“There is, therefore, a twofold eating of the flesh of Christ, one spiritual, of which Christ treats especially John 6:54, which occurs in no other way than with the Spirit and faith, in the preaching and meditation of the Gospel, as well as in the Lord’s Supper, and by itself is useful and salutary, and necessary at all times for salvation to all Christians; without which spiritual participation also the sacramental or oral eating in the Supper is not only not salutary, but even injurious and damning [a cause of condemnation].
“But this spiritual eating is nothing else than faith, namely, to hear God’s Word (wherein Christ, true God and man, is presented to us, together with all benefits which He has purchased for us by his flesh given into death for us, and by His blood shed for us, namely, God’s grace, the forgiveness of sins, righteousness, and eternal life), to receive it with faith and appropriate it to ourselves, and in all troubles and temptations firmly to rely, with sure confidence and trust, and to abide in the consolation that we have a gracious God, and eternal salvation on account of the Lord Jesus Christ. [He who hears these things related from the Word of God, and in faith receives and applies them to himself, and relies entirely upon this consolation (that we have God reconciled and life eternal on account of the Mediator, Jesus Christ), – he, I say, who with true confidence rests in the Word of the Gospel in all troubles and temptations, spiritually eats the body of Christ and drinks His blood.]
“The other eating of the body of Christ is oral or sacramental, when the true, essential body and blood of Christ are also orally received and partaken of in the Holy Supper, by all who eat and drink the consecrated bread and wine in the Supper—by the believing as a certain pledge and assurance that their sins are surely forgiven them, and Christ dwells and is efficacious in them, but by the unbelieving for their judgment and condemnation, as the words of the institution by Christ expressly declare, when at the table and during the Supper He offers His disciples natural bread and natural wine, which He calls His true body and true blood, at the same time saying: Eat and drink. For in view of the circumstances this command evidently cannot be understood otherwise than of oral eating and drinking, however, not in a gross, carnal, Capernaitic, but in a supernatural, incomprehensible way; to which afterwards the other command adds still another and spiritual eating, when the Lord Christ says further: This do in remembrance of Me, where He requires faith [which is the spiritual partaking of Christ’s body].” [Concordia Triglotta. Page 995. Emphasis in the original]
In short, one kind of “eating” (John 6:54) is receiving Jesus Christ in faith. Another kind of eating receives Jesus’ body and blood in, with, and under the bread and wine.