1 John 4:6 We are of God: he that knoweth God heareth us; he that is not of God heareth not us. Hereby know we the spirit of truth, and the spirit of error.
Ephesians 5:9 (For the fruit of the Spirit is in all goodness and righteousness and truth;
John 14:17 Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you
1 John 5:6 This is he that came by water and blood, even Jesus Christ; not by water only, but by water and blood. And it is the Spirit that beareth witness, because the Spirit is truth.
...Jesus says...
John 16:13,14
Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, [that] shall he speak: and he will shew you things to come.
He shall glorify me: for he shall receive of mine, and shall shew [it] unto you.
(Ask the Holy Spirit, the Spirit of Truth, to reveal Himself to you)