Everyone knows that a newborn baby needs mom. When a baby is born the first thing they need from mom is nourishment. They need to nurse. If you walked into the room and put a chunk of steak in little Peter's mouth he'd choke on it because he isn't ready.
So the reasoning goes for some people who deny the Eucharist to newly baptized infants. The Lord's Supper is clearly solid food that is only meant for those who know their catechism by heart, can reflect on what they believe, and can explain it to their pastor.
On the surface it might make some logical sense, but it simply is not consistent with what Scripture teaches. The Apostle Paul actually teaches that the Lord's Supper is part of the milk that nourishes infants in Christ. Don't believe me? Check this out.
"But I, brothers, could not address you as spiritual people, but as people of the flesh, as infants in Christ. I fed you with milk, not solid food, for you were not ready for it. And even now you are not yet ready, for you are still of the flesh." - 1 Corinthians 3:1-3 (ESV)
In Chapter 11 Paul continues,
"For I received from the Lord what I also delivered to you, that the Lord Jesus on the night when he was betrayed took bread, and when he had given thanks, he broke it, and said, “This is my body, which is for you. Do this in remembrance of me.” In the same way also he took the cup, after supper, saying, “This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me.” For as often as you eat this bread and drink the cup, you proclaim the Lord's death until he comes." (Emphasis mine)
Did you catch it? In the same letter Paul reminds them that he fed the Corinthians with milk, not solid food, because they weren't ready for it. Were they already receiving the Lord's Supper? Yes. Were the receiving solid food yet? No. So is the Lord's Supper solid food? It can't be! It must be milk.
Paul rebukes the Corinthians for playing with their food in chapter 11. They were misusing what he delivered to them. Paul wants them to become mature in their faith. He wants to impart to them the solid food which is the more advanced catechesis available to those who advance in their faith.
But he can't do that, because their divisions and fighting show him they still need the basics. For right now those babes in Christ need a steady diet of milk, which includes the Lord's Supper, a gift from their mother, the Church, who gave them new birth in the waters of baptism. The Lord's Supper is not steak for the newly baptized to choke on but milk to help them grow and mature.
So if someone, Lutheran or otherwise, says the Lord's Supper is the solid food, they haven't read their Bibles very closely. The Lutheran slogans of "Scripture Alone" and that "Scripture interprets Scripture" fall short of truth if such basic insights are missed, or intentionally ignored.
The Scripture says one thing, but Lutherans argue something else. This position of denying the Eucharist to babies demonstrates that what often happens when we try to interpret Scripture is that we start with our own conclusions and read those back into the Bible. This is why we need the Church!
Among Confessional Lutherans, those preconceived ideas are found in the Book of Concord. And if there is an error, they cannot correct themselves because they are bound to the tradition in the Book of Concord. This causes a situation where sometimes obvious Biblical truths must be ignored or explained away. Scripture alone sounds good, but in practice it is never alone. And Scripture is actually more at risk of being lost, ignored or warped with this mindset.
In the Orthodox Church there are no passages of Scripture that need to be avoided or compromised for personal or denominational benefit. The Bible is quite clear here. The Eucharist is milk, not solid food.
Don't give the babies steak, that's true. It'd kill them. They're not ready for advanced teaching and counsel on the spiritual life. They're learning to eat and walk. They're not ready to be great missionaries like Paul. They're not ready to be spiritual fathers living in the wilderness. They're not ready to be priests or bishops. They're ready for the life-giving "spiritual milk", the true Body and Blood Christ, that they may have His life in them and learn to walk in newness of life.
Give them the milk they need: the true Body and true Blood of Christ.