Martin McGuinness should return to Northern Ireland politics this week a somewhat chastened figure. His adventure into the Irish presidential election failed to rid him and Sinn Fein of the ghosts of the past.

On the contrary, it merely reminded us that there are too many questions unanswered and many issues unsettled despite the peace process.

Mr McGuinness may blame the Dublin media and establishment for treating him with unfair disrespect given his power-sharing role at Stormont. Certainly he was subjected to a degree of intense scrutiny which is rarely applied in Northern Ireland.

However, Mr McGuinness asked for it from the moment he said that his campaign for the presidency had the support of victims of IRA violence. He played the peace card but it was trumped. Victims in the south came out to oppose his candidacy rather than support him.

Sinn Fein’s greatest weakness – its lack of transparency – was exposed during the presidential election. Whoever they were, the victims of the IRA supporting Mr McGuinness for president were well outnumbered by those who very publicly voiced their opposition to him. Old sores were reopened as when he was confronted by the son of Irish army soldier Patrick Kelly shot dead by the IRA in 1983. Mr McGuinness heard also that the family of Garda Jerry McCabe did not consider him a suitable candidate.

As the decades pass, brutal facts become blurred. Sinn Fein’s political ducking and weaving continues, hiding the full truth, regretting rather than apologising, denying responsibility, trying to justify the unjustifiable.

One bit of Mr McGuinness seems to be in a state of denial that he ever did anyone much harm or was associated with people who did.

Another bit of him seems to be very proud of his militant actions and that of his colleagues. And a third bit of him, which was fully on display in the Republic, proclaimed him as the ultimate peace-maker, bridge-builder and hands across the divide leader.

All of this begs a question which many people in the south including the Dublin media wanted to know. Would the real Martin McGuinness please stand up? In Northern Ireland the answer does not appear to matter anymore. We have stopped asking the awkward questions because we know the answers will not be forthcoming. We don’t want to rock the political boat. We want to get on with our lives in peace as if nothing untoward had ever happened.

The Irish presidential election put on display the pain and resentment which still smoulders just underneath the surface of this island. The pain is that of the victims of violence. The resentment is that those who were engaged in violence have not come clean about their past.

Martin McGuinness falls into that category. For all the impressive leadership of Mr McGuinness at Stormont, having him as Irish president was not just one step too far but many.

The lesson which Sinn Fein might care to take from the presidential campaign is that trust can never be taken for granted. It has to be earned. Denying his past, as Mr McGuinness did, was not seen as conducive to building the future.

The mistrust about Sinn Fein, its leaders and their links with the IRA still runs deep. The bona fides of Sinn Fein remain in doubt because it sends out confusing signals – one minute appearing to deny and distance itself from the past, the next continuing to excuse or even hero-worship the deeds of the IRA.

If Mr McGuinness will forgive the pun, it appears that he jumped the gun in standing for the Irish presidency. If his intention was merely to raise the profile of Sinn Fein in the southern political scene, that was a cynical abuse of an election for a head of state. If he believed that he could win, he made a serious misjudgment.

The electorate have told him that Ireland is not ready for the kind of instant unity Sinn Fein appears to offer nor would be comfortable with him in Aras an Uachtarain.

Perhaps the real message from our friends in the Republic is that more needs to be done to unify Northern Ireland.