The English word mortal is derived from the Latin word for death, mortis. Ironically, living humans are referred to as "mortals," or "deaths" - a stark commentary on what a brief, fragile existence we all have. "Mortal life" is almost a contradiction. The good news (Gospel literally means good news) is that all humans have an opportunity to be immortal, having life that not only will never end, but will be gloriously free of all susceptibility to the illnesses and injuries, and the pain and suffering that went along with it, that made them mortal.
When and How Mortals Can Find Immortality
Jesus Christ is The Way, the only Way, to immortality:
"Jesus saith unto him, I am the way, the Truth, and the Life: no man cometh unto the Father, but by Me" (John 14:6 KJV)
"But is now made manifest by the appearing of our Saviour Jesus Christ, Who hath abolished death, and hath brought life and immortality to light through the Gospel" (2 Timothy 1:10 KJV)
"Howbeit for this cause I obtained mercy, that in me first Jesus Christ might show forth all longsuffering, for a pattern to them which should hereafter believe on Him to life everlasting. Now unto the King eternal, immortal, invisible, the only wise God, be honour and glory for ever and ever. Amen." (1 Timothy 1:16-17 KJV)
Immortality will be freely given to the obedient at the times of Judgment (to understand when and why those times, plural, are, see "When Will You Be Judged?" in the Fact Finder question below), while the disobedient will be sent to absolute oblivion:
"But after thy hardness and impenitent heart treasurest up unto thyself wrath against the day of wrath and revelation of the righteous judgment of God; Who will render to every man according to his deeds: To them who by patient continuance in well doing seek for glory and honour and immortality, eternal life: But unto them that are contentious, and do not obey the Truth, but obey unrighteousness, indignation and wrath" (Romans 2:5-8 KJV)
"And I saw a great white throne, and him that sat on it, from whose face the earth and the heaven fled away; and there was found no place for them. And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works. And the sea gave up the dead which were in it; and death and hell delivered up the dead which were in them: and they were judged every man according to their works. And death and hell were cast into the lake of fire. This is the second death. And whosoever was not found written in the book of life was cast into the lake of fire"
The obedient through all the ages will be resurrected on the day of The Return Of Jesus Christ; the obedient ones alive that day will be changed to spirit, to immortality, along with them (see Resurrections):
"Now this I say, brethren, that flesh and blood cannot inherit the Kingdom of God; neither doth corruption inherit incorruption."
"Behold, I show you a mystery; We shall not all sleep, but we shall all be changed, In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed. For this corruptible must put on incorruption, and this mortal must put on immortality. So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory. O death, where is thy sting? O grave, where is thy victory?" (1 Corinthians 15:50-55 KJV)
With immortality comes true life, life that truly means life, that is free of all of the physical and psychological burdens that made humans mortal:
"And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away." (Revelation 21:4 KJV)
Fact Finder: What are all of the dead doing right now? Where are they? (b) Why are there going to be different times of resurrection?
(a) See What Happens When You Die? (b) See When Will You Be Judged?