Why is the Bible full of that funny English?

Dear Zambia,
Thou, woe, hast, brethren, betrothed, bs...
I mean come on! if you got something to say why not speak in plain normal English so that everybody will understand without having to sit there scratching their scrotum
Thou, woe, hast, brethren, betrothed, bs...
I mean come on! if you got something to say why not speak in plain normal English so that everybody will understand without having to sit there scratching their scrotum