"Not everyone believes in a book written over 50 years ago."
So? Not everyone believes the Earth is spherical, they are convinced it is flat, but their disbelief does not change reality.
You may not believe in the Word of God, but the Word of God believes in you.
Hebrews 4:12-13
For the Word of God is living
and active
and sharper than any two-edged sword,
and piercing as far as the division of soul
and spirit,
of both joints
and marrow,
and able to judge the thoughts
and intentions of the heart.
And there is no creature hidden from His sight,
but all things are open and laid bare to the eyes of Him with Whom we must give account.
- - -
I have been studying the Bible for some time now, and one of the things that strengthens my faith in it, and in God, is how closely those who do not "believe[] in a book written over 50 years ago" follow the "script" found within. Unregenerate sinners cannot help but sin precisely as outlined in the Scriptures, and this in spite of today's sinners believing that they are so much more advanced and intelligent and sophisticated than the sinners of 2000 years ago. Nothing has changed in the hearts and minds of mankind, and the Word of God has everyone pegged down to their very core.