THE HOLY GHOST WITNESSES ABOUT GOD TO BELIEVERS....

"Now,we have received,not the spirit of the world,but the spirit which is of God;that we might know the things that are freely given to us of God.
Which things also we speak,not in the words which man's wisdom teacheth,but which the Holy Ghost teacheth;comparing spiritual things with sipirtual.
but the natural man receiveth not the things of the Spirit of God:for they are foolishness unto him:neither can he know them,because they are spiritually discerned
But he that is spiritual judgeth all things,yet himself is judged of no man."
1 Corinthians 2:12-15