That bears a little textual examination.
You set the Scriptures against themselves, sure indication you do not correctly understand them.
Let's begin with the first use of "immortal God" in 1Timothy.
It occurs in 1Ti 1:17: "Now to the King eternal, immortal, invisible, the only God."
The Greek word translated "immortal" here is aphthartos, which means "incorruptible."
The text states that God is "incorruptible."
So what does that mean? How does it mean "immortal"?
Well, God is physically "incorruptible" (because he has no body) which, therefore, makes him immortal, does not die.
God is also a morally "incorruptible" spirit, because he is God.
The text is stating that God is both a morally and physically incorruptible (aphthartos) spirit, and all spirits are immortal.
Now let's look at its use in 1Ti 6:16:
"God. . .who alone is immortal."
The text is stating that God alone is the incorruptible (1Ti 1:17) immortal being.
How do we know that?
Because God is the author of Scripture (2Ti 3:16,) and God does not contradict himself.
And God is not the only immortal being, because angels are immortal, and demons are immortal.
So the text means something else.
In light of 1Ti 1:17, where incorruptible has been translated immortal, we see what is meant in 6:16.
God is the only morally incorruptible/immortal being.
So 1Ti 6:16 does not disagree with other Scripture which reveals angels and demons are immortal.
But even though the angels are immortal, they could be, and were, corrupted in the heavenly rebellion.
So the NT reveals that all spirits are immortal. . .God, angels, demons and human spirits
(Php 1:23; Heb 12:18, 22-24; Mt 22:31-32; Lk 16:22-26).
But God is the only incorruptible/immortal spirit.
And then these nine Scriptures are still on the table unaddressed.
2) Then there is what Jesus said:
Mt 22:31-32 - "In the account of the bush (Lk 20:37-38), have you not read what God said to you, 'I am (present tense) the God of Abraham, the God of Isaac and the God of Jacob. He is not the God of the dead but of the living."
Two hundred years after the death of the patriarchs, God declared he is (present tense) the God of the patriarchs, Abraham, Isaac and Jacob (Ex 3:6). Since he is (present tense) the God only of the living, and not the God of the dead, what part of the patriarchs are still living?
Lk 16:22-26 - "The time came when the beggar man died and the angels carried him to Abraham's side. . .he called to him, 'Father Abraham, have pity on me and send Lazarus to. . .cool my tongue, because I am in agony in this fire.'
But Abraham replied. . .'If they do not listen to Moses and the Prophets, they will not be convinced even if someone rises from the dead.' "
Jesus presented the rich man in hell, with he and Abraham conversing with one another after their deaths.
He presented their spirits as conversing with one another because their spirits are immortal.
Lk 8:51 - "If anyone keeps my word,he will never see death."
Well, all those to whom Jesus spoke those words are now dead.
And God told Adam that the day he ate of the fruit he would die, but he lived for centuries.
So what died, and what did not die?
Jn 5:24 - "Whoever hears my word and believes him who sent me has eternal llife. . .he has crossed over from death to life."
So what was dead? . . .it wasn't their bodies.
From what death did they cross over?
3) We find the same thing in the epistles:
1Jn 3:14 - "We know we have passed from death to life, because we love our brothers. Anyone who does not love remains in death. . .no murderer has eternal life in him."
Again, what was dead? . . .it wasn't their bodies.
From what death did they pass?
Col 2:13 - "When you were dead in your sins. . .God made you alive with Christ."
Eph 2:1,3 - "You were dead in your transgressions and sins. . .by nature objects of wrath."
Again, what was dead? It wasn't their bodies.
Php 1:23 - "I am torn between the two: I desire to depart and be with Christ which is better by far, but it is more necessary for you that I remain in the body."
The NT plainly states that when believers die, they are with Christ, apart from their body.
So what part of them is with Christ, apart from their body?
Heb 12:18, 22-24 - "You have not come to a mountain that is burning with fire. . .You have come to Mount Zion. . .You have come to God, the judge of all men, to the spirits of righteous men made perfect, to Jesus the mediator of a new covenant. . ."
The NT reveals that the spirits of former righteous believers (e.g., Abel and Noah, vv.4, 7) are immortal
and are waiting for the resurrection.
When you have addressed the above Scriptures, we will revisit Lk 8:55.