I've heard some say that the world is only about 6000 years old.
Where does this figure, or something of that order of magnitude, come from?
How was it calculated?
I couldn't find that figure in the Bible?
Is it necessary to believe this figure to be a Christian?
How old is the world... and how is your belief justified?
According to the Bible - life on Earth is only about 6000 years old.
However the "rocks" of earth are most certainly older since in Gen 1 the "start point" is an existing Earth already covered by water.
Gen 1:2 NASB " And
the earth was a formless and desolate emptiness, and darkness was over the surface of the deep, and the Spirit of God was hovering over the surface of the waters. 3 Then God said..."
Gen 1:2 NKJV
. 2 "The
earth was without form, and void; and darkness
was on the face of the deep. And the Spirit of God was hovering over the face of the waters. 3 And then God said ... "
Compare that to Jeremiah 4's description of the millennium future to Jeremiah's day.
Jer 4:
23 I beheld
the earth, and indeed it was without form, and void;
And the heavens, they
had no light.
24 I beheld the mountains, and indeed they trembled,
And all the hills moved back and forth.
25 I beheld, and indeed
there was no human,
And all the birds of the heavens had fled.
26 I beheld, and indeed the fruitful land
was a wilderness,
And
all its cities were broken down
At the presence of the Lord,
By His fierce anger.
27 For thus says the Lord:
“The whole land
shall be desolate;
Yet I will not make a full end.
28 For this shall the earth mourn,
And the heavens above be black,
Because I have spoken.
I have purposed and will not relent,
Nor will I turn back from it.