Humanity has been "predestined" to hear and believe the good news of their salvation, and, upon believing they become sealed with the power of that promise.
I have heard much teaching about the Holy Spirit over the years. The various teachings on the Holy Spirit by religious institutions is confusing. I understand “Holy Spirit” as the POWER of God at work.
Humanity's “mortal” condition is terminal and so we all die. Afterward, however, we are "predestined" to be made alive and immortal by the Holy Spirit (power) of God. Then we will be "changed" at our resurrection into a new “spiritual body". It is a promise from God and it is the predestined hope of humanity.
“So also is the resurrection of the dead…it is sown a natural body, it is raised a SPIRITUAL body. If there is a natural body, there is also a SPIRITUAL body. So also it is written, the first man, Adam, became a living SOUL, the last Adam became a life-giving SPIRIT. However, the spiritual is not first, but the natural; then the spiritual. The first man is from the earth, earthy; the second man is from heaven…Now I say this, brethren, that flesh and blood cannot inherit the kingdom of God; nor does the perishable inherit the imperishable. Behold, I tell you a mystery…we will all be changed, in a moment, in the twinkling of an eye, at the last trumpet; for the trumpet will sound, and the DEAD will be raised imperishable… when this…mortal has put on IMMORTALITY, then will come about the saying that is written, DEATH is swallowed up in VICTORY.” (1 Corinthians 15:42-57)
“So also is the resurrection of the dead…it is sown a natural body, it is raised a SPIRITUAL body. If there is a natural body, there is also a SPIRITUAL body. So also it is written, the first man, Adam, became a living SOUL, the last Adam became a life-giving SPIRIT. However, the spiritual is not first, but the natural; then the spiritual. The first man is from the earth, earthy; the second man is from heaven…Now I say this, brethren, that flesh and blood cannot inherit the kingdom of God; nor does the perishable inherit the imperishable. Behold, I tell you a mystery…we will all be changed, in a moment, in the twinkling of an eye, at the last trumpet; for the trumpet will sound, and the DEAD will be raised imperishable… when this…mortal has put on IMMORTALITY, then will come about the saying that is written, DEATH is swallowed up in VICTORY.” (1 Corinthians 15:42-57)
That is the "message of truth, the gospel of your salvation".