Why do we endure sufferings?
If we look at scriptures, Jesus consistently says, "Any one who gives up mother, father, brother, sister, children, houses, fields for my sake..." The key phrase here is for my sake.
Thus sufferings should all be viewed through the eyes of faith. We suffer for Jesus. Sufferings is not a test from the Lord to see how strong our faith is. The basic truth is that God knows everything. If he had to test us to see how strong our faith is, then it means that God does not know everything - and this is insulting God.
Another common reason for enduring sufferings is that there will always be something better. We are hoping for something better in the future. If this is our reason, then there is a tinge of selfishness in this. This reason means that we endure sufferings because there is something to gain out of it.
Personally, I think the main reason for enduring suffering is because we believe that this is what God thinks is the best for our purification. We do not need to know the reason for the suffering as long as we know that this is the Lords will, we humbly submit to it - trusting that the Lord has his reasons for this. Why do we trust the Lord then?
Do we trust him because we know that he will give us something better? Again this goes back to the second argument. If this is the reason, then there is a bit of selfishness in it. I think we trust the Lord because of who he is. Not because of our love for him but because he is trustworthy.
In my early days with the Lord, there were things that clouded my faith. But now, It seems to me that the Lord wants us to accept him as he is. And I think this is where I often struggle with him. But blessed be the Lord because he is faithful. He continues to reveal himself patiently and slowly until one day, we shall see him as he is.