I think that all of life is a struggle for faith. Life presents things to us that almost make it impossible to believe. I guess that is part of the mystery of faith.
Often justice seems to be something that God works over time instead of in the moment/hour. This dynamic really causes most of us to stumble because bad things happen to the innocent and faithful ... delayed justice seems like no justice at all.
Trusting God in and after bad experiences can be a difficult thing to navigate because of the temporal injustice that we have suffered. Such was Job's struggle - he was declared blameless by God and yet experienced a level of perceived divine injustice that most of us cannot relate to. In the end God didn't explain the why of the injustice. Such is the nature of temporal injustice.
Justice for Job came at the end of the book when God affirmed Job and restored his life. Justice was delayed but justice came. Often this is not the case though ... often people die at the hands of injustice. I think that this is where faith in the goodness of God has to kick in. We will persevere in faith if we believe that God is good ... if we know that He loves and cares for us.
The cross: this is where I often end up when justice seems to have escaped me ... when life is difficult and overwhelms me. I look to the cost of my salvation - the extravagance of the love of Jesus on the cross ... I cannot get past it ... His love for me and His goodness gives me hope ... even when justice is delayed.