God had one Son on earth without sin, but never one without suffering. Augustine
God can use suffering to help us turn from sin
1 Peter 4:1-2
Therefore, since Christ suffered in his body, arm yourselves also with the same attitude, because he who has suffered in his body is done with sin. As a result, he does not live the rest of his earthly life for evil human desires, but rather for the will of God.
God can use suffering to make us fruitful
But the Lord said to Ananias, "Go! This man is my chosen instrument to carry my name before the Gentiles and their kings and before the people of Israel. I will show him (Paul) how much he must suffer for my name.
No pain, no palm; no thorns, no throne; no gall, no glory; no cross, no crown. William Penn
God can use suffering to make us Christ-like
I want to know Christ and the power of his resurrection and the fellowship of sharing in his sufferings, becoming like him in his death.
The Spirit himself testifies with our spirit that we are God's children. Now if we are children, then we are heirs -- heirs of God and co-heirs with Christ, if indeed we share in his sufferings in order that we may also share in his glory.
God can use suffering to bless the church
Now I rejoice in what was suffered for you, and I fill up in my flesh what is still lacking in regard to Christ's afflictions, for the sake of his body, which is the church.
God can use suffering to strengthen us
2 Corinthians 12:10
That is why, for Christ's sake, I delight in weaknesses, in insults, in hardships, in persecutions, in difficulties. For when I am weak, then I am strong.
God can use suffering to make us a blessing to others
2 Corinthians 1:3-6
Praise be to the God and Father of our Lord Jesus Christ, the Father of compassion and the God of all comfort, who comforts us in all our troubles, so that we can comfort those in any trouble with the comfort we ourselves have received from God. For just as the sufferings of Christ flow over into our lives, so also through Christ our comfort overflows. If we are distressed, it is for your comfort and salvation; if we are comforted, it is for your comfort, which produces in you patient endurance of the same sufferings we suffer.
God can use suffering to show us we are in Christ
"I tell you the truth," Jesus replied, "no one who has left home or brothers or sisters or mother or father or children or fields for me and the gospel will fail to receive a hundred times as much in this present age (homes, brothers, sisters, mothers, children and fields-- and with them, persecutions) and in the age to come, eternal life.
2 Timothy 3:12-13
In fact, everyone who wants to live a godly life in Christ Jesus will be persecuted, while evil men and impostors will go from bad to worse, deceiving and being deceived.