John 16:33

“I have said these things to you, that in me you may have peace.  In the world you will have tribulation.  But take heart; I have overcome the world.”

Jesus opened up to the disciples, very plainly, that the reason He was here was because of the love of God for His people and the reason He had to leave was to send the Holy Spirit which would comfort us in all situations that we would endure in our lifetimes.  He promised peace, as a matter of fact, peace that passes all understanding, a peace that each of us will know as we trust in Him.  Yes we will have tribulation, sicknesses, and troubles in the world but the clincher is, Jesus has overcome sin and evil in this world.  How do we get that reassurance? Putting our faith and trust in Him.