He becomes your Teacher. Jesus said when the Spirit of truth comes, He shall teach you all things. He didn't say 'some things,' but ALL THINGS. Glory to God! Anything in this life, anything about life, anything about God, ANYTHING at all, the Holy Ghost can teach you if you will ask or let Him. He will open up the Word of God to you and unveil the realities of God to you. He will be your Teacher. He will let you know what to do. When the Holy Ghost takes over your life, you will be different.