Psalm 37:4 is misused in Word of Faith teaching as a blank-check promise to receive material desires

Out of context, Psalm 37:4 — "Delight yourself in the Lord and He will give you the desires of your heart" — is used as a formula: if I rejoice in God, God will give me whatever I want (house, car, financial prosperity). This actually encourages coveting and lack of contentment, which the New Testament explicitly prohibits.