The Bible contains a great deal of material couched in a number of genres. It contains poetry, figurative speech, simile and metaphor, parables, and history. Each genre has its own uses and significance. It is very important to interpret each passage according to its genre and context. To take literally something that is intended poetically or figuratively can mislead as badly as taking figuratively that intended as literal. Take this illustration of the literal image of the beloved in Song of Solomon:
https://imgur.com/O56BsZqNot lovely but grotesque.
I suggest a slightly different take on the Law/Gospel duality. Law tells us what we should do, think, or feel. The Gospel tells us what God has done for us and what that means for us. The Law can easily be taught by ahistorical stories, fables, or parables. Gospel, since it recounts what others have done for us, must be rooted in historical fact, although the implication can be illustrated by fable or parable. The Law tells us that we are to be like the ant not the grasshopper, the king who forgives his embezzling servant not the unforgiving servant, the Samaritan who is neighborly not the Scribe and Levite who are not neighborly. It matters little if at all if any of those parables are rooted in historical events, they are illustrative of principle by which we are to guide our lives and our actions. The closest that those parables can come to Gospel is as a mundane illustration of the heavenly actions that God
has taken. If God has not done that it just becomes a story that perhaps moves
us to act with courage or compassion.
Would it make any sense for people to tell each other caught up in a tragic hurricane or wild fire to take heart and be encouraged because Superman will save the day like he has so many other times in so many places? If the story of God saving His people or Jesus dying and rising again are just stories, parables to illustrate something or encourage us, then the Gospel becomes just another Superman story and leaves it up to us to take heart and be courageous because no matter how much you believe, Superman ain't coming to save the day and Tinkerbell will not sprinkle her fairy dust no matter how much you clap or believe.
If the Gospel is not just nice stories to encourage us to save ourselves by engendering good thoughts and feelings, and acting accordingly, then they must be stories about actual events whereby God acted within our reality. In parables all we have is Law unless the parable points beyond itself to historical actions of God
for us to which we then respond as the parable suggests. We are to be like the forgiving servant who responded to his kings generosity in forgiving him by forgiving others, not because in the story the king was forgiving and acted to forgive, but because the story illustrated the reality to which it points, that God actually acted to forgive us much.