“Not only that, but we rejoice in our sufferings, knowing that suffering produces endurance, and endurance produces character, and character produces hope, and hope does not put us to shame, because God’s love has been poured into our hearts through the Holy Spirit who has been given to us.” -Romans 5:3–5
While the believer is at peace with God, the evidence of their personal experience shows that the world is not at peace with them. So Paul now uses the opportunity to speak to the sufferings of the believers and how it does not diminish but strengthen a true believer’s assurance of salvation.
We not only rejoice in the hope of the glory of God but we also rejoice in our sufferings. This is not a sadistic kind of rejoicing but an extension of that foundational rejoicing in the hope of the glory of God. This could be said that we also rejoice in the hope of the providence of God. As a believer, Paul says, we know our suffering produces something good because we have entered and now stand in his grace.
Suffering produces Endurance, which means the the capacity to hold out or bear up in the face of difficulty.
Endurance produces character. The word translated character means the genuineness of something proved by testing. It’s the idea of being without alloy; that is, metal purified by fire which has separated out the dross.
Character produces hope, which means confident expectation; or, having a reason for confidence respecting (a promise’s) fulfillment.
And Hope will never produce shame. This is a reference to Isaiah 28:16, “therefore thus says the Lord God, “Behold, I am the one who has laid as a foundation in Zion, a stone, a tested stone, a precious cornerstone, of a sure foundation: ‘Whoever believes will not be in haste.’”
And, the context is that the hope we have been given, will surely not disappoint us because it has been made sure by the manifestation of God’s love through the Spirit (Acts 2:17-18 Cf. Joel 2:28-29). In his letter to the Ephesians, Paul calls it the “guarantee of our inheritance” (note how similar the language Paul uses here is to the way he writes in Ephesians 1:11-14).
In sum, we rejoice in our hope while we simultaneously rejoice in our suffering because while we have not yet seen the fulfillment of that hope and we still suffer, we have a confidence that the promise will be fulfilled and the suffering will yield good because God gave us an earnest payment on his promise when he poured out to us the Holy Spirit.