Because your love is better than life, my lips will glorify you." - Psalm 63:2-3
In calling out to God for help David reminds himself (and the Lord) that he has already experience the power and glory of God in the sanctuary. This could be a way of reassuring himself that God is 'alive' and able to make himself known to his people. When you feel all alone and you struggle to see when God will show up, it is good to look back and be reminded that God is always present with us. This can in the temple or in the desert. Anyway, actually.
Verse 3 is David's way of saying that knowing the unfailing love of God is worth more to him than surviving his current ordeal. This knowledge would allow David to push through the pain of his trials. Or as one author states:
"Life without God is worse than death itself" (A. Anderson)
Living in Grace