John 16: Sadness and Joy

Jesus is about to die. He says that his disciples will become sad for some days (for his death), but after that, their grief will turn into joy (for his resurrection) as a woman in labor. 
It is very good to have prayers answered:

23-24 “This is what I want you to do: Ask the Father for whatever is in keeping with the things I’ve revealed to you. Ask in my name, according to my will, and he’ll most certainly give it to you. Your joy will be a river overflowing its banks!

The Spirit will be with the disciples, revealing more and more about Jesus. The Spirit will bring the disciples into communion with the Lord. Even though it is painful to live in this world, this sadness will be turned into joy due to the communion with the Father.