How much prayer?

Paul prayed three times for God to remove the thorn from his flesh, then stopped. He realized that God wanted him weak. Weakness was essential to his apostolic ministry, an enfleshment of his proclamation of the crucified Son.

Jesus tells a parable about an importunate widow who won’t take No for an answer, but who pesters the judge until he does justice.

Which is it? Pray a few times and leave it with God? Or keep praying until God knuckles under and does what you want?

It depends on what’s requested. We pray promises. Paul had not received a specific promise of relief from whatever that thorn was. Removing the thorn would, he initially thought, be an advantage. When God said No, he recognized that it was an advantage for the thorn to stay.

We have received promises concerning justice. God is the judge of the earth who does right. When we pray for justice, we don’t stop until we see it done. That is, we don’t stop praying for justice until final justice is done at the last day.