I know exactly what I should be doing and I cannot make myself start. Where does motivation even come from?

“And as he lay and slept under a juniper tree, behold, then an angel touched him, and said unto him, Arise and eat. And he looked, and, behold, there was a cake baken on the coals, and a cruse of water at his head. And he did eat and drink, and laid him down again. And the angel of the LORD came again the second time, and touched him, and said, Arise and eat; because the journey is too great for thee.”

Elijah had just seen fire fall on Mount Carmel, then ran for his life, sat down under a tree and asked to die. God's response is not a rebuke and not a new assignment. He is fed twice and allowed to sleep, and only afterwards is the journey ahead even mentioned. That order is worth noticing when you cannot make yourself move at all.

“Come unto me, all ye that labour and are heavy laden, and I will give you rest. Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls.”

Jesus says this to ordinary Galileans worn down by religious demands they could never meet and by lives that were physically hard. The image of a yoke was familiar to all of them: two animals harnessed together, the stronger one carrying the weight. He does not offer the removal of work. He offers a different way of carrying it, alongside him.