What was the black-winged deity of love? What secrets this masterpiece reveals about the rebellious artist

The young boy screams while his head is forcefully gripped, a large thumb pressing into his face as his father's powerful hand holds him by the neck. This scene from Abraham's Sacrifice appears in the Uffizi Gallery, creating distress through Caravaggio's chilling portrayal of the tormented youth from the scriptural account. It seems as if Abraham, instructed by God to sacrifice his offspring, could snap his spinal column with a solitary twist. Yet the father's preferred method involves the metallic steel knife he holds in his remaining palm, ready to slit the boy's throat. A definite element remains – whoever posed as Isaac for this breathtaking work displayed extraordinary expressive skill. Within exists not just fear, surprise and pleading in his darkened eyes but additionally deep grief that a guardian could betray him so completely.

The artist adopted a familiar biblical tale and made it so fresh and raw that its horrors appeared to unfold right in view of you

Viewing in front of the artwork, observers recognize this as a actual countenance, an precise record of a young model, because the same boy – recognizable by his tousled locks and almost black eyes – features in two additional works by Caravaggio. In each case, that richly expressive face commands the composition. In Youth With a Ram, he gazes playfully from the darkness while embracing a lamb. In Amor Vincit Omnia, he smirks with a hardness learned on the city's streets, his black plumed wings demonic, a unclothed child creating riot in a affluent dwelling.

Victorious Cupid, currently displayed at a British museum, represents one of the most discomfiting masterpieces ever painted. Observers feel completely disoriented gazing at it. Cupid, whose arrows inspire people with frequently painful desire, is shown as a very real, vividly lit unclothed figure, standing over overturned items that include stringed devices, a music score, plate armor and an builder's T-square. This heap of possessions echoes, intentionally, the mathematical and construction equipment scattered across the floor in Albrecht Dürer's engraving Melencolia I – except here, the melancholic mess is created by this grinning deity and the turmoil he can release.

"Affection sees not with the eyes, but with the soul, / And thus is feathered Love painted sightless," wrote the Bard, just prior to this work was created around the early 1600s. But the painter's Cupid is not unseeing. He stares straight at the observer. That countenance – sardonic and ruddy-faced, looking with bold assurance as he struts naked – is the identical one that screams in fear in Abraham's Test.

When the Italian master created his multiple portrayals of the same distinctive-looking kid in Rome at the dawn of the 17th century, he was the highly celebrated religious painter in a metropolis enflamed by Catholic revival. Abraham's Offering demonstrates why he was sought to decorate sanctuaries: he could take a biblical narrative that had been portrayed numerous times previously and render it so new, so unfiltered and visceral that the horror seemed to be happening directly in front of you.

However there existed another aspect to Caravaggio, apparent as quickly as he came in Rome in the winter that ended the sixteenth century, as a artist in his early twenties with no mentor or supporter in the urban center, just talent and boldness. The majority of the paintings with which he caught the sacred metropolis's eye were anything but holy. What could be the very first hangs in the UK's National Gallery. A young man opens his red mouth in a yell of pain: while reaching out his dirty digits for a cherry, he has instead been attacked. Boy Bitten By a Lizard is sensuality amid squalor: observers can discern Caravaggio's gloomy room mirrored in the murky waters of the glass container.

The adolescent wears a pink blossom in his hair – a emblem of the erotic commerce in early modern art. Venetian artists such as Tiziano and Jacopo Palma depicted courtesans holding flowers and, in a painting destroyed in the WWII but known through images, Caravaggio represented a renowned woman courtesan, clutching a bouquet to her bosom. The meaning of all these floral signifiers is obvious: sex for purchase.

What are we to make of Caravaggio's erotic depictions of youths – and of one adolescent in specific? It is a question that has divided his commentators ever since he achieved widespread recognition in the 1980s. The complex historical truth is that the artist was neither the homosexual hero that, for instance, the filmmaker presented on film in his 1986 film about the artist, nor so completely pious that, as some art scholars unbelievably assert, his Boy With a Basket of Fruit is in fact a likeness of Jesus.

His initial paintings indeed make overt sexual suggestions, or even propositions. It's as if Caravaggio, then a destitute youthful creator, identified with Rome's prostitutes, offering himself to survive. In the Uffizi, with this thought in consideration, observers might turn to another early creation, the 1596 masterpiece Bacchus, in which the deity of alcohol gazes calmly at the spectator as he starts to untie the black ribbon of his robe.

A several annums after the wine deity, what could have motivated Caravaggio to paint Victorious Cupid for the artistic collector the nobleman, when he was at last becoming nearly respectable with prestigious church projects? This unholy non-Christian deity revives the erotic provocations of his early paintings but in a more intense, unsettling way. Half a century afterwards, its hidden meaning seemed obvious: it was a representation of the painter's companion. A English visitor saw Victorious Cupid in about 1649 and was told its subject has "the physique and countenance of [Caravaggio's|his] own boy or assistant that laid with him". The identity of this adolescent was Cecco.

The painter had been deceased for about forty years when this story was documented.