Emin's crucifixion is the greatest painting since Lucian Freud

Halfway through the Royal Academy's Summer Exhibition, I was woken up by Jesus (but more on this, shortly).

- Jonathan Jones

The whole place came to life and more and more good stuff leapt out from the 1,600 works on view.

What's that upside-down stag? It's by the 87-year-old German master Georg Baselitz. As for those convex mirrors above your head, reflecting you and the floor in radical foreshortening, that's an installation by Cornelia Parker. In the same room hang eviscerated animal carcasses hooked up on chains, made from textiles by Tamara Kostianovsky.

But it's Jesus who lifts this exhibition out of the ordinary. He moves towards you like a shark in Tracey Emin's painting The Crucifixion. And like a shark, he is frightening. I thought art had lost its capacity to shock. But what is more shocking than a celebrated 21st-century artist sincerely painting the Passion?

Emin's talent is still raw and here she has painted her masterpiece. If you doubt her, see this. If you love her, see this. It's a big painting of the three crosses on the hill of Golgotha. Christ is flanked by two other crucified figures, one of whom is a woman - the only departure from tradition. Emin is a fan of north European art, including Munch. Here she echoes the intense and macabre Three Crosses of the German Renaissance painter Lucas Cranach.