"Be sober, be vigilant, because your adversary the devil walketh about as a roaring lion, seeking whom he may devour." (1 Peter 5:8) "but each person is tempted when they are dragged away by their own evil desire and enticed." (James 1:14)
Fiery Coals can be defined for purposes of this devotional as the heroic impetus that leads to excessively or unexpectedly bold and/or dramatic behaviors.
It's easy to justify or rationalize our bombastic actions by attributing the underlying fiery coals to God, as if heated passions could only be the result of His stirring. But when coals that get fired up, build steam, and erupt excessively and unexpectedly, they are more generally stirred by forces other than God at work inside and on us.
How would one know if fiery coals of inner passion were from God? Well, the passions would be matched by corresponding external signs of circumstance (unaided by personal desires, advantages or manipulations); consistent with the Law of God (unmolested toward expediency or so-called relevance); and matched in prayer (as opposed to merely public proclamations of prayer). If all of that lines up, then the fiery coals were, to the best of anyone's knowledge, probably stirred at God's altar.
The important question though, with every heroic impetus, is "what stirred the coals?". God's altar, Satan's furnace, or sins that had been pent up rather than put out? Remember, temptations do not produce sin, they only give a vent to sins fiery coals, already stirred and pent up in the heart.
