There is a practice among some Churches in only giving the bread/body of Christ in the Lord's Supper. As Lutherans we believe that when God gives you a gift, you take all that you can get.
Normally it is not good to be greedy. Certainly Paul warns us against getting drunk upon the blood of Jesus (I Corinthians 11).
However, when God offers you His body and blood for the forgiveness of your sins, to refuse one of them is to misunderstand the depravity in which you are cursed to live. You are a sinner, completely and totally. The only thing, and I mean the ONLY thing, working against this depravity is God's Word coming to you in the Scriptures, in Baptism, and in the Lord's Supper.
A similar question arises around baptism. If I already have believed the Word of God without baptism, then why do I need to be baptized?
BECAUSE JESUS SAID SO! Because in baptism God attaches you to the death and resurrection of Jesus Christ! Because in a world filled to the brim with sin you are walking around in a sin filled carcass just waiting to be devoured by Satan, the roaring lion.
You need all the help you can get. You need all the grace, all the promises, all the Gospel that Jesus has to offer. So when someone (a pastor) offers you the body and blood of Jesus, TAKE BOTH!
[Tomorrow: We stand for Marriage!]