On the signing of the Good Friday Agreement, US Senator George Mitchell famously said that that was the easy bit. The hard part was going to be implementing it. And he was right.
The twists and turns from April 10, 1998, to April 2013 have been many. At times, the process has collapsed. At other times, it looked as if securocrats and the wreckers were going to succeed and the whole peace process was going to unravel.
But, with patience and perseverance, 15 years after the Good Friday Agreement was achieved we have stable power-sharing arrangements and political institutions that are working and continue to enjoy popular support.
So successful has it been that the agreement is seen internationally as an example of how deep-rooted conflicts can be resolved.
International delegations are regular visitors to the Assembly and unionist and republican leaders frequently travel to trouble-spots around the world to speak about our unique agreement.
Of course, it isn't a perfect agreement. It was, after all, a compromise between conflicting political positions after decades of violence and generations of division.
Unlike the efforts that governments had concocted before – from Sunningdale in December 1973 through to the Anglo-Irish Agreement in 1985 – the Good Friday Agreement was genuinely comprehensive and inclusive and addressed the broad range of issues that had been previously ignored.
It deals with constitutional issues, political matters and institutional issues. It put in place a mechanism to hold a border poll to address the issue of partition.
It also set up political structures that provide for the sharing of power, while including checks and balances to prevent a recurrence of past political abuses.
It secured remarkable progress in the areas of policing and justice, demilitarisation and arms, discrimination and sectarianism, equality, human rights and the Irish language. The underlying ethos of the agreement and the major difference between it and all its predecessors is that equality lies at its core.
Since 1998, there have been further negotiations. The unionist leaderships have sought to minimise the implementation of the agreement. Republicans have argued for maximum implementation.
As a result and, in particular, because of the failure of the British and Irish governments to fulfil their obligations, there are a number of outstanding issues arising from the agreement, including a Bill of Rights for the north of Ireland.
This is not a nationalist, or a unionist, issue. A Bill of Rights would offer protections for the most vulnerable; it would respect the diversity of our community and would have equality at its very core.
Other outstanding issues include an all-island Charter of Rights, the establishment of the North-South Consultative Forum, the introduction of an Acht na Gaeilge (Irish language Act) and a resolution to the issue of OTRs.
The British Government has also failed to act on its Weston Park commitment to hold an independent inquiry into the killing of human rights lawyer Pat Finucane and, at the same time, has allowed the securocrats to continue to abuse human rights, most clearly in the continued detention of Marian Price and Martin Corey.
But it is in respect of a victim-centred truth and reconciliation process that much work still needs done.
This will be a huge challenge. Sinn Fein believes that the best way of doing this is through the establishment of an Independent International Truth Commission.
The two governments, former combatants and those in leadership across Ireland and Britain need to be part of such a process. There can be no hierarchy of victims.
The people of this island need a genuine process of national reconciliation. There can be no going back. The tiny minorities who want to cling to the past must be rejected. Sectarianism must be tackled and ended.
The promise of the Good Friday Agreement for a new society in which all citizens are respected and where fairness and justice and equality are the guiding principles has to be advanced.