'Unknown' in the Bible

For as I passed by, and beheld your devotions, I found an altar with this inscription, TO THE UNKNOWN GOD. Whom therefore ye ignorantly worship, him declare I unto you.

For he that speaketh in an unknown tongue speaketh not unto men, but unto God: for no man understandeth him; howbeit in the spirit he speaketh mysteries.

He that speaketh in an unknown tongue edifieth himself; but he that prophesieth edifieth the church.

Wherefore let him that speaketh in an unknown tongue pray that he may interpret.

For if I pray in an unknown tongue, my spirit prayeth, but my understanding is unfruitful.

Yet in the church I had rather speak five words with my understanding, that by my voice I might teach others also, than ten thousand words in an unknown tongue.

If any man speak in an unknown tongue, let it be by two, or at the most by three, and that by course; and let one interpret.

As unknown, and yet well known; as dying, and, behold, we live; as chastened, and not killed;

And was unknown by face unto the churches of Judaea which were in Christ: