6 Bible Verses about Testing Spirits

Beloved, believe not every spirit, but try the spirits, whether they are of God; because many false prophets have gone forth into the world.

and to another, workings of mighty deeds; and to another, prophecy; and to another, discerning of spirits; to another, various kinds of tongues; and to another, interpretation of tongues.

In this ye know the Spirit of God: every spirit that confesses that Jesus Christ hath come in flesh is of God; and every spirit that confesses not Jesus is not of God; and this is the spirit of the Anti-Christ, of which ye have heard that it is coming, and now it is in the world already. Ye are of God, little children, and have overcome them; because greater is He Who is in you, than he that is in the world.read more.
They are of the world; for this cause they speak of the world, and the world hears them. We are of God; he that knows God hears us; he that is not of God hears us not: from this we know the spirit of truth and the spirit of error.

And these were more noble than those in Thessalonica, in that they received the word with all readiness of mind, examining the Scriptures daily, whether these things were so.

but prove all things, hold fast that which is good.

and that, from a babe, you have known the holy Scriptures, which are able to make you wise unto salvation through faith that is in Christ Jesus. Every Scripture inspired of God is also profitable for teaching, for reproof, for correction, for instruction in righteousness; that the man of God may be complete, thoroughly furnished for every good work.