As David fled from Saul, he went for help to Ahimelech the priest. He needed food and wanted to consult with the Lord, and it happened that he also got Goliath's sword there. All this resulted later in Ahimilech's death and the deaths of all of Ahimilech's family.
Psalm 104 is a companion with Psalm 103. This psalm also starts and ends with the same refrain, the same one as in Psalm 103. This psalm expounds on the majesty of God, especially as seen in His creation.
21Then the young lions roar for their prey,
stalking the food provided by [You, O] God.
34May all my thoughts be pleasing to [You, O God//him],
for I rejoice in [in You, O Lord//the LORD].
The power behind the new lives that God wants us to live is the Holy Spirit. A side observation here: We can see that the Holy Spirit can equally be called the Spirit of God and the Spirit of Christ (vs. 9-11). Having God's Spirit in our lives does not mean that we will not suffer. In the second half of today's reading, note the Holy Spirit's role for us in the midst of our sufferings. Then at the end, note the wonderful promises given to us!
5Those who are dominated by the sinful nature [just] think about sinful things, but those who are controlled by the Holy Spirit think about things that please the Spirit.
9But you are not controlled by your sinful nature [any longer]. You are controlled by the Spirit if you have the Spirit of God living in you. (And remember that those who do not have the Spirit of Christ living in them do not belong to him at all.)