Romans 5:5 Such hope never disappoints or deludes or shames us, for God’s love has been poured out [This is written in the perfect passive tense – we don’t have to do anything to make the love flow] in our hearts through the Holy Spirit Who has been given to us.
What if what we hope for doesn’t happen? If we are focused inward on the circumstance our heart will become sick. “Hope deferred maketh the heart sick (grieve)” (Prov 13:12). But as we wait for this hope to be fulfilled, the love of God is “poured out into our hearts”. So if we focus upward our heart is healed with His love. Remember in Romans, how the heroes of the faith often did not see their hopes fulfilled until after their deaths!