John 16:13-14 (ESV)
When the Spirit of truth comes, he will guide you into all the truth, for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come. He will glorify me, for he will take what is mine and declare it to you.
The truth into which the Holy Spirit guides us is the truth about Jesus Christ. The Spirit helps us through patient practice to discern right from wrong.
1 Corinthians 2:10 (ESV)
these things God has revealed to us through the Spirit. For the Spirit searches everything, even the depths of God.
The “depths of God” refers to God’s limitless nature and wonderful plan- Jesus’ death and resurrection- and to the promise of salvation, revealed only to those who believe what God says is true.