Good question. The joy of eternal life is Jesus. Let me explain. All people seek joy (happiness).
Blaine Pascal, the great mathematician, once wrote:
All men seek happiness. This is without exception. Whatever different means they employ, they all tend to this end. The cause of some going to war, and of others avoiding it, is the same desire in both, attended with different views. This is the motive of every action of every man, even of those who hang themselves.All people seek joy. And they often try to find it in worldly things such as relationships, possessions, status or wealth. The Bible, however, teaches us that the ultimate, most satisfying joy comes from Jesus.
The most basic way to understand this truth is to recognize that apart from Christ, you and I deserve judgment and thus separation from the source of all things good (including joy): God. Jesus came on a mission to save us - not only from hell - but so that we can have joy in HIM. When we know we are loved, cherished and accepted by God in Christ, we do not need to seek other forms of joy. Indeed, we find joy in our children and careers, but they are not the ultimate source of our joy; Christ is! [If you've been attending our services, we've been going through the Gospel of John, which tells us that Jesus is the water that quenches all thirst and the food that eternally satisfies
Another truth is that eternal life does not start when you die; it starts now. You don't get the joy after you die. When you receive Christ, he fills you up with joy NOW. Even if sorrow and tragedy strike you, knowing that God loves you in Jesus and that one day you will be with Him in heaven (a place where there is no suffering, pain or sin) gives you this joy.
[Answered by Pastor HM]
Recommends: Dr. John Piper has done a wonderful job talking about joy in his message here. If you have some time, try to listen to some of the messages on joy by Pastor Mark Driscoll.