5And by the power of the Holy Ghost ye may know the truth of all things.
The Holy Ghost can teach us the truth of ALL things! If there is any truth out there to be found, it's through the Holy Ghost that we can obtain that knowledge. So... how can we know for ourselves that the Holy Ghost is teaching us truth? Christ taught us in John 14:26 that the Holy Ghost is known as the Comforter.
26But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
That's one way in which the Holy Ghost communicates to us: it brings us comfort.
The Apostle Paul taught us about the fruits of the Spirit in Galatians 5:22-23. Now I don't know about y'all, but I'm a city slicker and I don't know ANYthing about trees! The only way I'm going to know if it's an apple tree is if it has apples on it. The only way I'll know if it's an orange tree is if it has oranges. The same principle applies to these spiritual fruits:
22But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith,
23Meekness, temperance: against such there is no law.
A modern-day apostle, President Boyd K. Packer, taught: