“Tribulations by definition are anti-hope. If they felt hopeful in themselves they wouldn’t be tribulations. What’s the underlying secret of actually growing in hope through tribulation?
Paul answers in the next line: ‘Because the love of God has been poured out within our hearts through the Holy Spirit who was given to us’ (v.5). God’s love ‘has been poured out in our hearts.’ The tense of this verb means that God’s love was poured out in our hearts in the past (at our conversion) and is still present and active.
God did demonstrate his love for us in giving his own Son to die once for all in the past for our sins (v. 8). But he also knows that this past love must be experienced as a present reality (today and tomorrow) if we are to have patience and character and hope. Therefore he not only demonstrated it on Calvary, he goes on demonstrating it now by the Spirit. He does this by opening the eyes of our hearts to ‘taste and see’ the glory of the cross and the guarantee that it gives that nothing can separate us from the love of God in Christ Jesus (Romans 8:39).”
[Excerpt from John Piper’s Daily Devotional, found here, emphasis mine]