What is the meaning of word translated immortality in 1 Corinthians 15:53?

Question

What is the meaning of immortality in 1 Corinthians 15:53?

For the perishable must clothe itself with the imperishable, and the mortal with immortality.

Answer 1

The word translated "immortality" is ἀθανασία athanasia which is the opposite of θάνατος thanatos = death.

Thus, ἀθανασία athanasia simply and literally means "undying". The word occurs just three times in the NT with same meaning each time, 1 Cor 15:53, 54, 1 Tim 6:16.

Thayer notes this about ἀθανασία athanasia -

ἀθανασία (ας ἡ (ἀθάνατος), immortality: 1 Corinthians 15:53; 1 Timothy 6:16 where God is described as ὁ μόνος ἔχων ἀθανασίαν, because he possesses it essentially — 'ἐκ τῆς ὀικείας οὐσίας, οὐκ ἐκ θελήματος ἄλλου, καθάπερ οἱ λοιποί πάντες ἀθάνατοι Justin,quaest, et resp. ad orthod. 61, p. 84, Otto edition. (In Greek writings from Plato down.)

To expand on Thayer's point, I observe what John tells us in 1 John 5:11, 12 -

And this is that testimony: God has given us eternal life, and this life is in His Son. Whoever has the Son has life; whoever does not have the Son of God does not have life.

This is a direct consequence of John's remark in John 1:4, "in Him [Jesus] was life"; John 14:6 and "I am ... the life"; John 6:35, "I am the bread of life", etc.