Blessed is a man who perseveres under trial; for once he has been approved, he will receive the crown of life which the Lord has promised to those who love Him. (James 1:12)
As creatures of comfort, we are always trying to get out from under the pressure that difficulty brings. The blessing God brings, however, he brings to those who remain under the trials he sends. He desires that we remain under the difficulty until it succeeds in the matter for which he sent it.
And let endurance have its perfect result, so that you may be perfect and complete, lacking in nothing. (James 1:4)
Our initial response of welcoming difficult circumstances is challenged by the fact that they linger. Welcoming them in does not send them away. Lasting joy comes when we see the result of putting up with them long enough for God to use them to produce his desired effect in us.
Consider it all joy, my brethren, when you encounter various trials, knowing that the testing of your faith produces endurance. (James 1:2-3)
Difficulty can be welcomed with joy not because it is enjoyable to endure, but because it produces in us the much needed quality of endurance. It is amazing what we can endure when we have a clear view of the end and God always uses the wisest means to accomplish his ends.