Who exactly was Caravaggio's black-winged deity of desire? What insights this masterwork uncovers about the rogue artist

The youthful lad screams while his head is forcefully gripped, a large digit pressing into his cheek as his father's mighty hand holds him by the neck. This moment from Abraham's Sacrifice appears in the Florentine museum, creating unease through the artist's chilling rendition of the suffering child from the scriptural narrative. The painting seems as if the patriarch, instructed by God to sacrifice his offspring, could break his neck with a solitary twist. However the father's preferred method involves the silvery steel blade he holds in his remaining hand, ready to cut the boy's throat. One certain element stands out – whoever modeled as the sacrifice for this breathtaking work demonstrated extraordinary acting skill. There exists not just dread, shock and pleading in his shadowed gaze but also profound grief that a protector could betray him so utterly.

The artist adopted a well-known scriptural story and made it so vibrant and raw that its horrors seemed to happen right in front of you

Viewing before the artwork, observers identify this as a actual countenance, an precise depiction of a adolescent model, because the same boy – recognizable by his tousled hair and almost dark pupils – appears in several other paintings by the master. In each case, that highly emotional visage dominates the scene. In Youth With a Ram, he peers playfully from the darkness while embracing a lamb. In Victorious Cupid, he smirks with a hardness learned on Rome's streets, his black feathery wings sinister, a unclothed child running riot in a well-to-do residence.

Amor Vincit Omnia, presently displayed at a London gallery, represents one of the most embarrassing artworks ever painted. Viewers feel completely disoriented gazing at it. The god of love, whose arrows fill people with frequently agonizing longing, is shown as a extremely real, vividly lit unclothed form, straddling toppled-over objects that include stringed devices, a music manuscript, metal armour and an architect's T-square. This heap of items resembles, intentionally, the geometric and architectural equipment strewn across the ground in Albrecht Dürer's engraving Melencolia I – save in this case, the gloomy mess is created by this grinning deity and the turmoil he can unleash.

"Love sees not with the vision, but with the mind, / And thus is winged Love painted sightless," wrote Shakespeare, shortly prior to this work was produced around the early 1600s. But the painter's Cupid is not blind. He stares straight at the observer. That face – ironic and ruddy-faced, looking with brazen assurance as he struts naked – is the same one that screams in fear in Abraham's Test.

As Michelangelo Merisi da Caravaggio created his three portrayals of the same distinctive-looking kid in Rome at the dawn of the 17th century, he was the highly acclaimed religious artist in a city ignited by religious renewal. Abraham's Offering demonstrates why he was commissioned to decorate sanctuaries: he could adopt a biblical narrative that had been depicted many occasions previously and make it so new, so raw and visceral that the horror appeared to be happening immediately in front of you.

Yet there was another aspect to Caravaggio, apparent as soon as he arrived in Rome in the winter that concluded 1592, as a painter in his initial 20s with no mentor or supporter in the urban center, only skill and audacity. Most of the works with which he caught the holy city's attention were everything but devout. That could be the absolute earliest resides in the UK's art museum. A young man opens his crimson lips in a yell of agony: while stretching out his dirty digits for a cherry, he has instead been attacked. Boy Bitten By a Lizard is eroticism amid squalor: observers can discern the painter's gloomy room reflected in the murky waters of the transparent container.

The boy wears a pink blossom in his coiffure – a symbol of the sex trade in early modern art. Northern Italian painters such as Titian and Palma Vecchio portrayed courtesans grasping flowers and, in a work destroyed in the WWII but known through images, the master portrayed a famous woman prostitute, holding a posy to her bosom. The meaning of all these floral signifiers is clear: intimacy for sale.

What are we to interpret of Caravaggio's erotic depictions of youths – and of a particular boy in specific? It is a inquiry that has split his commentators ever since he achieved mega-fame in the 1980s. The complex historical truth is that the artist was neither the homosexual icon that, for example, the filmmaker put on screen in his 1986 movie Caravaggio, nor so entirely devout that, as certain art scholars unbelievably claim, his Youth Holding Fruit is in fact a portrait of Jesus.

His early paintings indeed make overt erotic implications, or even offers. It's as if the painter, then a penniless young artist, aligned with Rome's sex workers, selling himself to survive. In the Florentine gallery, with this thought in consideration, viewers might turn to another initial work, the sixteenth-century masterpiece the god of wine, in which the god of wine stares calmly at the spectator as he begins to untie the black sash of his garment.

A few annums following the wine deity, what could have motivated the artist to create Amor Vincit Omnia for the artistic patron Vincenzo Giustiniani, when he was at last growing almost established with prestigious church commissions? This profane pagan deity revives the erotic provocations of his initial paintings but in a more intense, uneasy way. Half a century afterwards, its hidden meaning seemed obvious: it was a portrait of the painter's lover. A British visitor saw the painting in about the mid-seventeenth century and was told its subject has "the body & face of [Caravaggio's|his] own boy or assistant that laid with him". The name of this boy was Cecco.

The painter had been deceased for about 40 annums when this story was documented.