This is a psalm of confidence as opposed to a confidence psalm. By that I mean the psalmist is confident in God who counsels and makes one secure and promises eternal pleasures while those who run after other gods reap the rewards of a Ponzi scheme. The only thing multiplied by their investment is sorrow. The other gods of psalm 16 are the Canaanite deities like Ba’al. I’m confident that the worship of Ba’al is not a great temptation today but running after other gods still is. Martin Luther defines other gods like this: “whoever trusts and boasts great skill, prudence, power, favor, friendship, and honor has also a god...” So when we run after possessions or power or prestige or pleasure we do so at the expense of investment in the One who makes the heart glad and the tongue rejoice and the body rest secure. The other gods call us to run after them while the true God pursues and precedes us for God’s promise is backed by the security of the One who abandoned to the grave made even death obedient to Him. It is because God is ahead of us in death and behind us in life that we with the psalmist can say we will not be shaken. So make a wise investment today, stop running after other gods and let the Lord catch up to you.