How does using the Biblical term cause confusion? Man is dust. The breath or spirit in man is God. Those combined form a soul.
The soul is not immortal. Tell me, why would God promise immortality to believers if they were already immortal? What point would that serve?
God said Genesis,
And the LORD said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years.
Man is flesh not a spirit.
We're not eternal. The eternal life that is given by Christ comes in the next age, not this one. It's at the Resurrection.
Then Peter began to say unto him, Lo, we have left all, and have followed thee. And Jesus answered and said, Verily I say unto you, There is no man that hath left house, or brethren, or sisters, or father, or mother, or wife, or children, or lands, for my sake, and the gospel's, But he shall receive an hundredfold now in this time, houses, and brethren, and sisters, and mothers, and children, and lands, with persecutions; and in the world to come eternal life. But many that are first shall be last; and the last first.
Notice the receive in this time and that which is receive din the age to come. The word world is the word age. Eternal life is given in the age to come. That's at the Resurrection.
Paul wrote,
And as it is appointed unto men once to die, but after this the judgment: (Heb. 9:27 KJV)
It's the person being judged in the flesh. The person dies, they remain dead until the time of judgement.
Marvel not at this: for the hour is coming, in the which all that are in the graves shall hear his voice,
29 And shall come forth; they that have done good, unto the resurrection of life; and they that have done evil, unto the resurrection of damnation.
30 I can of mine own self do nothing: as I hear, I judge: and my judgment is just; because I seek not mine own will, but the will of the Father which hath sent me. (Jn. 5:28-30 KJV)
12 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.
13 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.
14 And death and hell were cast into the lake of fire. This is the second death.
15 And whosoever was not found written in the book of life was cast into the lake of fire. (Rev. 20:12-21:1 KJV)