Because they have not learned that they are not dead

Lutero:

Where does Scripture say that Jesus prayed to Moses and Elijah? It doesn't!

But Scripture does depict Jesus speaking to Moses and Elijah. And that is the basis of our doctrine of the "Communion of Saints". 

Communion means "communicating". Look at number 3 in the Merriam Dictionary:

com·mu·nion

noun \kə-ˈmyü-nyən\

Definition of COMMUNION

1
: an act or instance of sharing

2
a capitalized : a Christian sacrament in which consecrated bread and wine are consumed as memorials of Christ's death or as symbols for the realization of a spiritual union between Christ and communicant or as the body and blood of Christb : the act of receiving Communionccapitalized : the part of a Communion service in which the sacrament is received

3
: intimate fellowship or rapport : communication

Where does Scripture say that Jesus "summoned" Moses and Elijah? It doesn't!

 Nor do we claim to summon any Saint either. We simply believe that the Saints are here with us. Scripture says:

Hebrews 12:1

Wherefore seeing we also are compassed about with so great a cloud of witnesses, let us lay aside every weight, and the sin which doth so easily beset us, and let us run with patience the race that is set before us,
Hebrews 12:21-23

King James Version (KJV)
²¹ And so terrible was the sight, that Moses said, I exceedingly fear and quake
²² But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels,
²³ To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect,

2 Kings 6:16-18

King James Version (KJV)
¹⁶ And he answered, Fear not: for they that be with us are more than they that be with them.
¹⁷ And Elisha prayed, and said, Lord, I pray thee, open his eyes, that he may see. And the Lordopened the eyes of the young man; and he saw: and, behold, the mountain was full of horses and chariots of fire round about Elisha.
¹⁸ And when they came down to him, Elisha prayed unto the Lord, and said, Smite this people, I pray thee, with blindness. And he smote them with blindness according to the word of Elisha.

And that is why what YOU do is completely different from what Christ did. If Mary or any other saint appears to you, you are welcome to talk to them. Until then, it is YOU who has painted yourself into a corner with your illogical and false accusations against me and against Jesus Christ! 

To whom are the dead alive? To God...not to you!

Is that what the Scripture said? Nope. 

1. As noted above, Christ spoke to Moses and Elijah in the company of Peter, James and John. Obviously they gave no indication of being dead.

2. Scripture does not say the Saints are only alive to God. Scripture says that all His Saints are alive.
Matthew 22:32

King James Version (KJV)
³² I am the God of Abraham, and the God of Isaac, and the God of Jacob? God is not the God of the dead, but of the living.

He is a God of the living.

3. To say that all are alive to God means that God is aware of even those in hell. But they are dead to us.

Now he is not God of the dead, but of the living, for all live to him.”
And do you know what this verse is about? It would seem you do not since you all you can think of is to use it as proof that you can pray to those who are DEAD TO YOU.

They are dead TO YOU. But not to us. We know that those whom God saves will remain part of His Body and will continue to communicate with us.

My argument is Biblical.

Your argument is Biblical in the sense that you are using the Bible. But your argument contradicts the Bible:

2 Peter 3:16

King James Version (KJV)
¹⁶ As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction. 

Because you contradict the Church:
Ephesians 3:10

King James Version (KJV)
¹⁰ To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God,

The Holy Spirit saw fit to call believers who have died the first death "the DEAD IN CHRIST"

And what does it mean to be "dead in Christ"?

John 11:26

King James Version (KJV)
²⁶ And whosoever liveth and believeth in me shall never die. Believest thou this?

Apparently you don't believe this basic Teaching of the Christian Faith.

You continue to make false accusations about what I have stated. In no way did I claim that Jesus broke the Old Law. It is only your inability to understand the difference between Moses and Elijah "appearing" to Christ vs. your practice of praying in your head to the dead in Christ. If Moses or Elijah or Mary or any other dead in Christ appear to you, feel free to talk to them. Until then, your prayers are in fact an attempt to contact the dead. Jesus did not do that. Catholics do.

We read the Scriptures differently than do you.

1. We read for Spiritual discernment:
1 Corinthians 2:14
But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.

2. Therefore, we do not get caught up in the letter of the Word:
2 Corinthians 3:6

King James Version (KJV)
⁶ Who also hath made us able ministers of the new testament; not of the letter, but of the spirit: for the letter killeth, but the spirit giveth life.

Now, all that you see in the details of the Transfiguration on the Mountain, is Jesus speaking to Moses and Elijah.

But we see much more:
1. Moses and Elijah are ALIVE! Although they had died centuries ago. They are still ALIVE!
2. They are speaking and communicating with Jesus.
3. Scripture says that Jesus is our example:
1 Corinthians 11:1

King James Version (KJV)
1 Be ye followers of me, even as I also am of Christ.

4. Therefore, in accordance with Scriptured, we are permitted to communicate with the Saints.

Why does Paul tell the Thessalonians not to grieve over those who have died in 1 Thess 4 if they are not dead to them?

That is precisely why? Because they have not learned that they are not dead to them. By grieving they act as though they have died. But he is correcting them. 

We, live by faith, not by sight:
2 Corinthians 5:7

King James Version (KJV)
⁷ (For we walk by faith, not by sight

Apparently, you believe only what you can see.

Sincerely,

De Maria