Today in Belfast I am going to be addressing a group of Northern Ireland's top business people men and women who are used to operating on the ground in Northern Ireland, not at the level of political rhetoric or vague absolutes, but rather at the coalface of practical reality.
And, as such, they know that the last three years have seen a transformation in the Northern Ireland economy a transformation not fully appreciated in the rest of the country.
Because Northern Ireland is no longer the basket case of the UK economy, only to be approached with the utmost caution. The only problem flying to Belfast these days is getting a seat in business class.
And that's for one very good reason. Northern Ireland today is a better place in which to live, work and do business. And the reason for that is very simple: the difference made by the Good Friday Agreement in the last three years.
The facts speak for themselves. Northern Ireland is now the fastest-growing economy in the UK. Unemployment is nearly 20 per cent lower than before the Agreement long-term unemployment nearly 30 per cent lower. Why? Because more people are prepared to invest in Northern Ireland plc over 2 billion pounds' worth promised in the last four years.
The reason is simple. Because people from around the world have recognised that Northern Ireland is in the process of becoming a normal, stable society in which people resolve their political differences across the table, not on the barricades or bomb site.
That is the bottom line. Northern Ireland is no longer seen as a hopeless case, but as society in which business people can thrive. But this new prosperity did not come about by accident. It is the direct result of the Agreement, the direct result of the courage, imagination and sheer grit that both the politicians and the people showed three years ago.
And they were right to do so. Because the Agreement has stood the test of time. Its fundamentals are as strong now as they were then. It remains the only show in town the only way to continue delivering the peace and prosperity Northern Ireland was denied for so long.
It has brought: inclusive government; local ministers making local decisions over local affairs, whether on education, the economy or how to handle foot and mouth; practical co-operation between North and South; a new police service which young people from every section of the community want to join; and at the heart of it all equality, human rights, and fair treatment.
It is a Northern Ireland in which people have the right to live in peace, to decide their own constitutional future, and to be treated fairly and equally, no matter what their faith, culture or tradition.
Those are the fundamentals of the Good Friday Agreement. That is what we all signed up to, and that is why hard-nosed business executives from around the world believe that they should invest in our future.
But, as with any credible balance sheet, we have to be honest. We have to acknowledge that the transition from concept to reality is a difficult one. There is no inevitability about success. The process of implementing the Good Friday Agreement has not been easy. For many it has caused pain, as they have seen prisoners released, and institutions they have respected and loved changed. For others, it has meant confronting compromise they rarely imagined. And for everyone, the beginning of the process of coming to terms with the past.
Given those challenges, progress has also been slower than some expected in the first flush of euphoria three years ago. We have not fully resolved issues such as policing, de-commissioning, and the smooth running of the institutions.
That is the debit side of the balance sheet, and we must be honest not only in facing up to that fact, but also in recognise the impact those unresolved issues have had on people in Northern Ireland, the people who invested their hopes in the Agreement.
With some, there is frustration or scepticism. Others, I suspect, have just switched off, disengaged. And I understand that sense of frustration.
But it is to ignore the very real progress we have made. Not only is Northern Ireland today a better place than it was three years ago, but the Agreement is still working. It still provides the means to resolve the remaining issues and allow us to reach agreement on policing, decommissioning, normalisation and the working of the institutions.
Nothing else holds out that prospect. Does anybody seriously believe that there is an alternative? If any of us wants to know what the future would hold for Northern Ireland without the Good Friday Agreement, all we have to do is look at the past.
Northern Ireland was not a prosperous place. Business people did not want to invest. Young people did not want to stay. The two traditions were caught in a vicious cycle of distrust and recrimination. They reached no agreement about the future until the Good Friday Agreement.
It did not end the distrust overnight, but it did provide the means of gradually bringing down the mental barricades. And it still does.
But how do we deliver the final product? We do it by completing the task, not by walking away. And that means everyone. It means the two governments recommitting themselves to making the Agreement work in all its aspects. And it means the parties doing likewise.
But it also means looking for support to the people who have invested most, and have most to lose if the Agreement does not work the people of Northern Ireland.
Three years ago, life was simpler. Hope was high and the choice was easier: yes, or no. Three years on, life is more complicated. We have seen the pain, the compromises, the difficulties involved in making the Agreement work, in moving from theory to reality.
It is no longer a matter of yes, or no. It is a more complicated choice, but the bottom line is the same.
With all its difficulties, all its hard choices, the Agreement remains the only guaranteed way to keep delivering a better Northern Ireland.
But the Agreement cannot do it of its own volition. Those brave local politicians, who have been prepared to take risks to make progress, cannot do it on their own. The governments cannot do it on its own.
The Agreement needs the active support of people in Northern Ireland just as much today as it did three years ago in the referendum.
The Agreement faces many threats. But the greatest danger it faces is that the people whom it ultimately benefits will begin to take these benefits for granted, will get bored with the constant argument, and will disengage.
This is not the time to disengage. It is not the time to despair. It is not the time to stay at home. This is the time to be positive. It is the time for people to make their voices heard.
The writer is Secretary of State for Northern Ireland