John 14 is some of the most comforting teaching in Scripture. The disciples had just learned that one would betray Jesus, Peter would deny Him, and Jesus was leaving. Jesus said, Don't let your heart be troubled. Believe in God. Believe also in me. Background: in ancient Israel, a groom would often prepare a room in his father's house and then return for his bride. Jesus promised to prepare a place and come again. His going away was for their good.
Thomas asked how they could know the way. Jesus answered, I am the way, the truth, and the life. No one comes to the Father, except through me. Jesus is not merely a guide pointing toward God. He is the way itself. When Philip asked to see the Father, Jesus said, He who has seen me has seen the Father. He was claiming perfect unity with God the Father.
Jesus then promised the Holy Spirit, called the Counselor or Helper. The Spirit of truth would dwell with them and be in them. Jesus would not leave them orphans. The Spirit would teach them all things and remind them of His words. That promise is why the disciples could later write the Gospels accurately. Jesus also promised that the Father and Son would make their home with those who love Him and keep His word. Finally, He said, Peace I leave with you. My peace I give to you; not as the world gives. The world's peace depends on circumstances, but Jesus' peace rests on Him.