Greetings Rebel,
Although I do not agree with many of the SDA teachings, including the two that you mention in your OP, I do believe that the soul is mortal. Perhaps a few Scriptures without getting involved in a discussion here on this topic:
 Genesis 2:7 (KJV): And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul. 
Genesis 2:17 (KJV): But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die. 
Genesis 3:19 (KJV): In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art, and unto dust shalt thou return. 
Daniel 12:2 (KJV):And many of them that sleep in the dust of the earth shall awake, some to everlasting life, and some to shame and everlasting contempt. 
Acts 2:31-32 (KJV): 31 He seeing this before spake of the resurrection of Christ, that his soul was not left in hell, neither his flesh did see corruption. 32 This Jesus hath God raised up, whereof we all are witnesses. 
I personally believe that it is an important subject, and worthy of careful consideration.
Kind regards
Trevor
		
		
	 
Thank you for sharing those very helpful texts.
Acts 2 is interesting because it shows that
 David is still there -even after the resurrection of Christ. Christ is not in the same state - David is left in the same state as he was at death. "dead and buried"
29 “Men 
and brethren, let 
me speak freely to you of the patriarch David, that 
he is both dead and buried, and his tomb is with us to this day.  30 Therefore,  being a prophet, and knowing that God had sworn with an oath to him  that of the fruit of his body, according to the flesh, He would raise up  the Christ to sit on his throne,  31
he,  foreseeing this, spoke concerning the resurrection of the Christ, that 
 His soul was not left in Hades, nor did His flesh see corruption.  32 This Jesus God has raised up, of which we are all witnesses.  33 Therefore  being exalted to the right hand of God, and having received from the  Father the promise of the Holy Spirit, He poured out this which you now  see and hear.
 34 “
For David did not ascend into the heavens, but he says himself:
‘The Lord said to my Lord,
“Sit at My right hand,
35 Till I make Your enemies Your footstool.”’
At no point does Peter say "David went to heaven when he died" or "David went to heaven after Christ was raised from the dead".
Genesis 2 vs Genesis 3 is interesting because it contrasts the word of God - with the word of satan.
Gen 2 - God said
 16 And the Lord God commanded the man, saying, “Of every tree of the garden you may freely eat;  17 but of the tree of the knowledge of good and evil 
you shall not eat, for in the day that you eat of it you shall surely die.”
Eve in Gen 3 referred back to the Word of God in Gen 2 - 
Gen 3:2 And the woman said to the serpent, “We may eat the fruit of the trees of the garden;  3 but of the fruit of the tree which 
is in the midst of the garden, God has said, ‘You shall not eat it, 
nor shall you touch it,
 lest you die.’”
Eve added the extension "nor shall you touch it" -- a mistake on her part.
And what was the Devil's counter doctrine?
Gen 3: 4 Then the serpent said to the woman, “
You will not surely die."
[FONT="]Ps 146:[/FONT]
  
[FONT="]2[/FONT][FONT="] I will sing praises to my God while I have my being. [/FONT]
  [FONT="]3 do not trust in princes, in [/FONT][FONT="]mortal man[/FONT][FONT="], in whom there is no salvation. [/FONT]
  [FONT="]4 his spirit departs, [/FONT][FONT="]he returns to the earth[/FONT][FONT="]; [/FONT][FONT="]in that very day his thoughts perish. [/FONT]
  [FONT="]5 how blessed is he whose help is the God of Jacob,[/FONT]
[FONT="]Ecclesiasties 9:5-6 they have no activity[/FONT]
  
[FONT="]5[/FONT][FONT="]For the living know that they will die; 
      But the dead know nothing[/FONT][FONT="], 
[/FONT][FONT="]And they have [/FONT][FONT="]no more reward[/FONT][FONT="], 
      For the memory of them is forgotten. 
       [/FONT][FONT="]6[/FONT][FONT="] Also their [/FONT][FONT="]love, their hatred, and their envy have now perished[/FONT][FONT="]; 
      Nevermore will they have a share 
      In anything done under the sun.[/FONT]
  
  [FONT="]Hence: Praise to God - ceases at death [/FONT]
  [FONT="]Ps 115:17
 the dead do not praise the Lord, nor do any who go down into silence; [/FONT]
  
[FONT="]18 but as for us, we will bless the lord from this time forth and forever. Praise the lord! [/FONT]
  
  [FONT="]No
 thanks or praise to God given by those 
that are dead. [/FONT]
  
  [FONT="]Is 38:18 “
for sheol cannot thank you, death cannot praise you; those who go down to the pit cannot hopefor your faithfulness. [/FONT]
  
[FONT="]19 “it is the [/FONT][FONT="]living who give thanks[/FONT][FONT="] to you, as I do today;[/FONT]
  
  [FONT="]No memory of God [/FONT]
  [FONT="]Ps 6:5
for there is no mention of you in death; in sheol who will give you thanks? [/FONT]
  
  [FONT="]Matt 22:23-34 Christ insists that
 “God is not the God of the dead”  To prove the doctrine of the resurrection.[/FONT]
I am not talking about soul annihilation at the first death - that happens at the second death Ezek 18:4 '
the soul that sins it shall die"