As the tributes to the Rev Ian Paisley flowed from former friends and opponents over the past few days, I was reminded of the phrase: live long enough and all is forgiven. Paisley's unlikely late embrace of power-sharing in Northern Ireland, which, lest we forget, assured him the post of first minister, thus finally assuaging his gargantuan ambition and ego, seems to have blinded most commentators to his long record of disruption, bigotry and rabble-rousing, not to mention his flirtations with paramilitarism.

Paisley was born in Armagh, the town I grew up in, and, as with Ballymena, where he lived, and indeed the whole of Northern Ireland, he felt he owned the place. In November 1968, he rallied several hundred men, armed with cudgels, in Armagh town centre to prevent the passing of a peaceful civil-rights march. It was a taster of much of what was to follow over the next 30-odd years, as the hellfire Free Presbyterian preacher-turned-politican wholeheartedly embraced the latter vocation without ever shedding the often grotesque certainties of the former.

What Paisley was for was all too obvious: the continuation of the "Protestant parliament and a Protestant state" that his predecessor, James Craig, the first prime minister of Northern Ireland, had enshrined. What Paisley was against was anything, real or imagined, that threatened the built-in bigotry and God-given certainties of that state. He railed against Rome, the papist Irish state across the border, equal rights and opportunities for Roman Catholics, British moderates of whatever hue, homosexuals (who can forget his Save Ulster from Sodomy campaign?) and any would-be unionist fellow travellers who did not share his tunnel vision and evangelical righteousness.

As far back as 1966, when he was already a household name in Northern Ireland for his antics – throwing snowballs at a visiting Seán Lemass, then Irish prime minister, objecting to a bridge in Belfast being named after the Queen instead of Carson – the Guardian noted: "If Mr Paisley has his way, there could well be a religious war here quite soon." Throughout the following decade, there were times when that did indeed seem to be his aim. To the horror of traditional, mainly middle- and upper-class unionists, he became the voice of a disaffected working-class constituency whose communal sense of certainty – "We are the people" was then the most common slogan – was matched only by the so-called siege mentality that Paisley, more than any other local politician, understood and exploited.

With his anti-Catholic demagoguery, he became the great inciter. He rallied the loyalist bully boys who attacked peaceful students with stones and cudgels on a protest march in 1968. He condoned the burning of working-class Catholic homes in Belfast. His incendiary rhetoric led many impressionable Protestant youths to join the UDA and UVF. Hugh McLean, a UVF member convicted of the murder of a young Catholic barman, Peter Ward, later said he regretted that he had "ever shared the name of Ian Paisley or decided to follow him". This reflected the views of many rank-and-file loyalists who came to view Paisley as a stirrer who then stood back when the inevitable violence ensued.

In 1973, Paisley aligned himself briefly to the neo-fascist Vanguard movement and, in 1981, appeared on a hillside with 500 men of the self-styled Third Force, some of them masked and wearing combat jackets. He was instrumental in the organising of the Ulster workers' strike that wrecked the first attempt at power sharing in 1974. It would take another 24 years of violence before the late epiphany that led him to accept the Good Friday agreement and all that followed.

As his late epiphany is celebrated, it may be worth remembering the long odyssey of disruption and demagogery that led him there. His was the voice of thunder against anything approaching a detente between moderate unionists and nationalists and, as such, the great wrecker of peace, of hope. For a long time – too long – that was his only legacy.