Being faithful to a promise or commitment can sometimes be very difficult. Things distract us or we just lose the momentum or willpower. God never loses faith in us. He watches over us and remains faithful, no matter what. The Lord is our Guardian who never sleeps.
Let our prayer be from Psalm 121
My help shall come from the LORD,
who made heaven and earth.
He will keep your foot from stumbling.
Your guard will never slumber.
No, he sleeps not nor slumbers,