A few months ago, the Lord had shown me a gigantic revelation: the wicked are burned up and destroyed forever, never to be remembered again. The modern Christian idea of "hell" is an incorrect one, for the Bible supports destruction with hundreds of instances that we will slowly divulge at a later time. (Note: We are not Jehovah's Witness, Seventh Day Adventist, or anything of the sort. We are Bible-believing and reading Christians who seek to be molded by God's Word, regardless of what the mainstream thinks about it.)
For now, I would like to establish the Biblical fact that man is a mortal soul, and that immortality is a gift that is given us from our Savior Jesus Christ. We will look mainly at 1 Corinthians 15:35-57, with additional supporting verses as they come to me. But first, let us define the meaning of the word "soul."
 And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.
Let us go to the original Hebrew to find the definition of "soul" in this context:
From H5314; properly a breathing creature, that is, animal or (abstractly) vitality; used very widely in a literal, accommodated or figurative sense (bodily or mental): - any, appetite, beast, body, breath, creature, etc
I did not include the entire definition here for the sake of brevity, but as you can see, it has nothing to do with immortality. It's simply a breathing creature; vitality. The Lord breathed into man, and he became a living creature. That's what this verse is saying.
Now, after a search with e-Sword (an amazing free piece of Bible software), we see that the word "soul" is mentioned 420 times in the Old Testament. 419 of these times it's the Hebrew word nephesh above. The one other instance of the word is found in Job 30:15, and this is all it means:
Feminine of H5081; properly nobility, that is, reputation: - soul.
So immediately we have established one single, solid definition of "soul" from the Old Testament. It's a breathing creature, something that has vitality. Nowhere is immortality implied.
 Then shall the dust return to the earth as it was: and the spirit shall return unto God who gave it.
Man returns to dust, his spirit (from the Hebrew word ruach, meaning breath; wind) returns to God who gave it. God giveth and taketh away.
As for the New Testament, every instance of the word soul comes from the Greek word "psuche:"
From G5594; breath, that is, (by implication) spirit, abstractly or concretely (the animal sentient principle only; thus distinguished on the one hand from G4151, which is the rational and immortal soul; and on the other from G2222, which is mere vitality, even of plants: these terms thus exactly correspond respectively to the Hebrew [H5315], [H7307] and [H2416]: - heart (+ -ily), life, mind, soul, + us, + you.
For examples in the Bible, check Matthew 10:28, 12:18, 16:26, and many more. I strongly suggest you purchase a Strong's Concordance if you haven't already. It gives us the ability to really dig into God's Word.
From our research into the New Testament, we see that it is in total harmony with the Old. Not a surprise, the Bible is one cohesive unit and should not be taken piecemeal. I could almost stop this study right now after showing the meaning of the soul. The Bible leaves no other alternatives for what it means. Nowhere is immortality implied. However, in the next part of this little study I will dive into 1 Corinthians 15 and shed further light on this subject, through the direction of the Lord. God bless you and thanks for reading!