"The Encyclopedia Brittanica says................"
On one hand you're saying God does not condone merging His teachings with human philosophies.................but then, you give us the Encyclopedia Britannica as your reference!
Lol - so why do you believe the Encyclopedia Britannica?

Who do you think wrote that encyclopedia?
Which is Authoritative? That encyclopedia............................ or the BIBLE?
There are many references in the Bible regarding the immortal soul.
Let me just give you the very basic.
These verses that connect, and corroborate with one another:
Genesis 2:7
Then the Lord God formed the man of dust from the ground and breathed into his nostrils the breath of life, and the man became a living creature.
Ecclesiastes 12:7
And the dust returns to the earth as it was, and the spirit returns to God who gave it.
Job 3:8
But it is the spirit in man, the breath of the Almighty, that makes him understand.
Psalm 146
3 Do not put your trust in princes,
in human beings, who cannot save.
4 When their spirit departs, they return to the ground;
on that very day their plans come to nothing.
The breath of God is what gave life to the form of man which is made from dust. Without God's breath, there wouldn't be life.
God's breath is the soul of man.
At the time of death, God's breath (soul) leaves the body and returns to GOD.
Why wouldn't the soul stay with the body?
Because the soul is not made from dust!
Matthew 10:28
And do not fear those who kill the body but cannot kill the soul. Rather fear him who can destroy both soul and body in hell.
1 Thes 5:23
Now may the God of peace himself sanctify you completely, and may your whole spirit and soul and body be kept blameless at the coming of our Lord Jesus Christ.
Rev 6:9
When he opened the fifth seal, I saw under the altar the souls of those who had been slain for the word of God and for the witness they had borne.