Surely God is good to Israel

13 All in vain have I kept my heart clean

    and washed my hands in innocence.

14 For all the day long I have been stricken

    and rebuked every morning.

Although Ps 73 was written three thousand some years ago, the temptation is perennial. When the wicked prosper, and the faithful suffer, it's tempting to join the winning team. If there were no afterlife, the temptation would be overwhelming.

11 And they say, “How can God know?

    Is there knowledge in the Most High?”

Their impudence is boundless and blasphemous. Yet it seems to be borne out by experience. No thunderbolts strike them down. 

15 If I had said, “I will speak thus,”

    I would have betrayed the generation of your children.

Unlike apostates, Asaph had the tact and discretion not to share his misgivings in public unless and until he found an answer. 

17 until I went into the sanctuary of God;

    then I discerned their end.

This is enigmatic. What happened in the sanctuary to prompt his epiphany? 

Although we might view the Solomonic temple as artistically inspiring, it functioned as a holy abattoir. The blood-spattered floor. Redolent with the stench of burning flesh. Blood and guts all day long. The spectacle of a gilded slaughterhouse isn't all that edifying. 

Perhaps, though, it was the time of evening prayer. Worshippers chanting the Psalter.

Or maybe he received a revelation of the afterlife, suddenly putting this life in perspective. Asaph was a prophet. 

18 Truly you set them in slippery places;

    you make them fall to ruin.

19 How they are destroyed in a moment,

    swept away utterly by terrors!

20 Like a dream when one awakes,

    O Lord, when you rouse yourself, you despise them as phantoms.

Some commentators think this refers to divine judgment overtaking the wicked in this life. But surely an attentive observer like Asaph was cognizant of the fact that the wicked don't necessarily or even routinely receive their comeuppance in this life. Indeed, that aggravating observation was what triggered his crisis of faith in the first place: 

4 For they have no pangs until death;

    their bodies are fat and sleek.

5 They are not in trouble as others are;

    they are not stricken like the rest of mankind.

They luxuriate in long, healthy, carefree lives. So it must look ahead to something beyond the grave. 

23 Nevertheless, I am continually with you;

    you hold my right hand.

24 You guide me with your counsel,

    and afterward you will receive me to glory.

25 Whom have I in heaven but you?

    And there is nothing on earth that I desire besides you.

26 My flesh and my heart may fail,

    but God is the strength of my heart and my portion forever.

Once again, some commentators offer a this-worldly rather than other-worldly interpretation of the affirmation. But that doesn't solve the problem Asaph posed at the outset. This life is the problem. If there is to be a resolution, then that demands a reversal of fortunes in the world to come–where the first shall be last and the last shall be first. A parallel afterlife for the faithful and the faithless. Their paths crisscross in this life, but diverge in the afterlife.