I suppose it has been coming for a while. I suppose other people recognised it about me long before I was prepared to admit it even to myself. Please understand: it's hard to let go of something that has been such a part of my identity for most of my life. It gave me a living and a purpose. And yes, I'm going to be embarrassed by all those smirking "told you sos".

But they were right and now I need to own up and come clean: I don't believe in God. And no, this is not some modern theologian's semantic dodge. The whole thing is rubbish; a set of bronze-age myths designed to keep the priestly caste in power and carefully engineered to feed off the insecurities of the weak and the ignorant.

And to think, I gave religion my best years – which is why I won't ever be a neutral sort of atheist. I know it from the inside: all the deceitful intellectual twists and turns, all the cons and the bullshit, all the hypocrisy. The way it treats women and gays. The way it pretends it has some sort of monopoly on virtue while abusing children and making people feel guilty about sex. The way it uses that weasel category of "faith" as a cover for a lack of proper intellectual justification.

All that manipulative stuff about "going to heaven" because it says so in a very old book (a book that constantly contradicts itself). To tell you the truth, most of them don't mean it anyway. And the ones that do are mad. No, I am going to make Richard Dawkins look like a model of calm. I hate religion, passionately. And it feels good finally to be able to say so publicly.

Am I being serious? Well, yes and no. Yes because, despite frequent assumptions to the contrary, many Christians do get atheism and feel its force. Indeed, from Job to Martin Luther to Dostoyevsky, some of the most vociferous expressions of hostility towards God hail from within the Christian tradition. The Roman Catholic church was built upon the rock of St Peter: but this very foundational figure was also the person who denied Christ over and over again. Even Jesus on the cross appears to have lost sight of the one he once called Father. "My God, why have you forsaken me?"

Nietzsche, for instance, got his famous "God is dead" phrase, via Hegel, from the words of a 17th-century German hymn: "O große Not, Gott selbst ist tot" – or "O great distress! God himself is dead!" In the Easter story, atheism is a moment within faith and not its contradiction. Hegel understood how a thing can also contain its opposite. Faith and non-faith have a dialectical relationship.

Today is Holy Saturday – that theological no man's land between the crucifixion and the resurrection where faith is traditionally absent. It is the one day of the year when Christians get to be atheists.

But I'm obviously not being entirely straightforward with you in pretending to be an atheist. I'm also still a fully paid-up believer. For even during those numerous moments in my priestly ministry when I have lost sight of my calling, even when I have given up, there is something that has not given up on me.

The point about the resurrection is that it represents the revival of what to all the world looks like a totally lost cause. The hope that first drove ordinary people to put down their nets and follow some strange itinerant preacher from Galilee turns out to be a great deal more robust than any strength of mind that His once enthusiastic follows were able to muster within themselves.

Even faith itself comes as a gift and not as something self-sustaining. And thank God for that. So we say: He is risen. Hallelujah.

Twitter: @giles_fraser