The four characteristics of God mentioned by David in Ps 36:5-10 are the wellspring of life:
God’s love. David reminds us that God’s love reaches to the heavens (Ps 36:5) and although we cannot actually measure God’s love with a ruler, the Bible reminds us of its vastness (see also Eph 3:17-19). It is priceless (Ps 36:7) and ultimately forms the basis of the security of our relationship with God, since nothing can separate us from His love. (Rom 8:37-39)
God’s faithfulness. David goes on to focus on God’s faithfulness, using the same metaphor of height: God’s faithfulness reaching to the skies. Love and faithfulness are frequently linked together in the Psalms (see Ps 40:11, Ps 57:3, Ps 85:10 for example) and remind us that a key part of love is dependability. God promises never to leave us or forsake us (Heb 13:5) and He who promised is faithful. (Heb 10:23) This brings security and stability to our lives, so that even if we are being buffeted by trials and temptation, we can still be sure of God’s faithfulness to us. (1 Cor 10:13)
God’s righteousness & justice. God will always do what is right (Gen 18:25) and we can trust Him to deal with the wicked! Habakkuk struggled to understand why injustice seemed to flourish (Hab 1-2); we often feel, like the child, ‘it’s not fair!’ Ultimately, however, we can leave justice to God because we know He is just.
God’s protection & preservation. The second half of verse 6 tells us that ‘You, Lord, preserve both people and animals.’ (Ps 36:6) David the shepherd knew what it was to care about the sheep; he fought the lion and the bear to protect the flock (1 Sam 17:33-35). His commitment to his flock and his care of them were simply a reflection of God’s commitment to and care of His people. Jesus, our good shepherd, gave His life for the sheep (John 10:11, 14-15) and we can find refuge under the shadow of God’s wings (Ps 36:7, see also Ps 91:1-2).
When we focus on these things, our lives are given hope and stability, security and joy.