Resurrection

Paul's theology on resurrection is well-known. There is little room for alternative interpretations. Therefore, I will simply collect the quotations he used in chapter 15 of the first epistle to the Corinthians.
φάγωμεν καὶ πίωμεν, αὔριον γὰρ ἀποθνῄσκομεν.
Let us eat and drink, for tomorrow we die. (1 Corinthians 15:32b)
Φάγωμεν καὶ πίωμεν, αὔριον γὰρ ἀποθνῄσκομεν. (Isaiah 22:13b)
This quotation is identical with Septuagint.
ἐγένετο ὁ πρῶτος ἄνθρωπος Ἀδὰμ εἰς ψυχὴν ζῶσαν
The first man Adam became a living being (1 Corinthians 15:45b)
ἐγένετο ὁ ἄνθρωπος εἰς ψυχὴν ζῶσαν. (Genesis 2:7b)
This quotation is nearly identical. The words in red had been added by the author of 1 Corinthians to make the meaning clearer.
κατεπόθη ὁ θάνατος εἰς νῖκος.
Death is swallowed up in victory. (1 Corinthians 15:54b)
κατέπιεν ὁ θάνατος ἰσχύσας,
He will swallow up death prevailing (Isaiah 25:8, LXX).
He will swallow up death forever (Isaiah 25:8, MT)
The author has rewritten the text. He changed the verb "to swallow" from active to passive.
ποῦ σου, θάνατε, τὸ νῖκος; ποῦ σου, θάνατε, τὸ κέντρον;
O death, where is thy victory? O death, where is thy sting? (1 Corinthians 15:55)
ποῦ ἡ δίκη σου, θάνατε; ποῦ τὸ κέντρον σου, ᾅδη;
Where is your punishment, O death? Where is your sting, O Hades? (Hosea 13:14c, LXX).
Where is your plagues, O death? Where is your ruin, O Sheol? (Hosea 13:14c, MT)
The Septuagint is a very good rendering of the Hebrew, adapting Sheol to Hades. The author of 1 Corinthians made one more change to render the text more inline with his thoughts. But why didn't he keep the word "Hades"?

My dear Advocate, the resurrection of Jesus is the foundation of our faith. Resurrection is also our hope in the future. Help us lead a life of charity, follow St. Paul's advice on love so that we will be worthy to share the eternal life You have prepared for us. Amen.