Life has always been gift and grace. God's grace is even bigger than we thought. John 21 demonstrates this truth to us through His love for Peter after his denial of Jesus as well as through His service to the disciples.
John 17 gives us the privilege of witnessing an intimate conversation between God the Son and God the Father. Jesus prays not only for His disciples then but for us as well.
It was hard enough for early Christians after most of the apostles died. Less than 40 years after Jesus' ascension, Jerusalem was leveled and the temple was destroyed. John writes to these persecuted Christians of the things to come.
We are saved and become Christians by believing in the atoning death and resurrection of Jesus. However, in order to grow and become mature as Christians we must abide in Him.
For three years the disciples were with Jesus and witnessed His miracles. They believed His message, but now He tells them He's leaving and they can't come with Him! What is going on?
John 13 marks a significant shift in Jesus' ministry. He's done numerous public signs to prove that He is the Christ and that it is through Him that one may have life. He now shifts to something different.