When Jesus came to earth, He had to face tribulation. Everyone who walks in His footsteps, is guaranteed to have to face the same thing.
When we came to realize that we were sinners, and in need for salvation, we accepted the Good Message of Jesus Christ with thankfulness. Our hearts were filled with joy now that we found eternal security, completely undeserved.
But pretty soon, we would find that not everyone would appreciate our newly found faith. We would find fellow human beings, and even spiritual entities, on our way trying to fight us down.
In the Bible, we can read how Jesus Christ has told us how we would be treated in exactly the same way as He was treated: with scorn, persecution, hatred and ultimately... with deadly torture.
We all have to face this in some way or another. It can be, that you're rejected for "intolerance" because you happen to know that Jesus is the only Way. It can be, that you are put in prison or put to death by antichrist forces because you don't follow wicked laws that say you cannot evangelize.
It's a guarantee: when you are born again, you will have to face tribulation.
Just like Jesus.
And when such tribulation comes, it will never be a joyous thing in the beginning. Every time you're rejected because you happen to love your Creator, is another scarf on your soul.
But still there is much joy, a very deep joy to be found within tribulation. Because when you are persecuted for His Name's sake, it's not about you at all. You are persecuted because in some mystical way, Jesus lives through us and He is the One they are actually persecuting.
But since they can't reach Him where He is now, they turn on His disciples. And knowing that the time is short, we can all expect tribulation to increase on a global scale.
Realizing this -true- nature of persecution and tribulation can therefore be a source of joy. It is a confirmation, that indeed we are the sheep of His pasture. And with that, we're blessed with eternal security that nobody can take away from us.