Anyone can claim to be a follower of Jesus, but Jesus gave us a way to measure whether or not our faith is real. If we truly have placed our faith in Jesus as Lord and Savior, then we WILL bear fruit.
As Jesus prepares His disciples for His departure from them, He promises them that He's not going to leave them helpless, nor will they be alone. He promises that His relationship with Him will continue to grow even though He's returning to His Father.
