That praying in tongues is a spiritual prayer language undefiled nor polluted
by our sinful natures is indirectly attested to by James in his epistle:
3 Behold, we put bits in the horses' mouths, that they may obey us; and we turn
about their whole body.
4 Behold also the ships, which though they be so great, and are driven of fierce winds,
yet are they turned about with a very small helm, whithersoever the governor lists.
5 Even so the tongue is a little member, and boasts great things. Behold, how great a matter
a little fire kindles!
6 And the tongue is a fire, a world of iniquity: so is the tongue among our members,
that it defiles the whole body, and sets on fire the course of nature; and it is set on fire of hell.
7 For every kind of beasts, and of birds, and of serpents, and of things in the sea, is tamed,
and hath been tamed of mankind:
8 But the tongue can no man tame; it is an unruly evil, full of deadly poison.
9 Therewith bless we God, even the Father; and therewith curse we men, which are made after
the similitude of God.
10 Out of the same mouth proceeds blessing and cursing. My brethren, these things ought not
so to be.
James 3: