There is always a time and place to do the right thing. The path to peace - and it has been a long and often painful journey - has provided many such opportunities.
Doing the right thing can be difficult, because it often means personal reflection and compromise; stepping into unknown territory to do something you never imagined you might do.
The well-worn phrase of no gain without pain has never been more true. While we all went through the pain-barrier on party-political compromise, prisoners, power-sharing and, of course, policing, we also witnessed the courage of political and personal compromise.
The courage and compromise which brought us to a much better place; a place I never thought I would see in my lifetime.
One of the great successes of the peace process has been the evolution of policing from what was the RUC to what is the PSNI.
I am very proud of my time as an RUC officer and of the work we did holding a line in extraordinarily difficult circumstances, but I know and respect the fact that other people will have different views.
Did we always get things right? Of course not. But, in my experience, we fought to keep people safe. And therein lies one of the key issues.
We - the RUC - were in a position in which we were seen to be fighting a war. A perception compounded by the fact that we were largely representative, in a physical sense, of one community; good, bad and indifferent.
I am also proud to have been a member of the PSNI. It has not evolved to fight a war, but has been developed and reconstructed to keep the peace. It's greatest success has been building on the foundations of the past and integrating and reshaping its workforce to reflect the society it serves.
Police officers are not invented; they are recruited. They are people with real lives and real families.
They should come from your street, village, town and city. When they belong, they share your hopes, fears and expectations.
Committed leadership is crucial now and we have seen real political and public leadership from Stormont, the GAA and the ICTU.
Our Chief Constable has made it clear that he can tackle these threats head-on and his team have made real investments in community-based policing.
As for commitment in the top team, it could not be better evidenced than by current Deputy Chief Constable Judith Gillespie passing up the significant financial rewards offered by early retirement via Patten, a route many of us would have grasped. Her presence will ensure the continuity of leadership that supports and sustains change.
Good people everywhere will be heartened by the cross-community gestures we have seen in the days following Ronan Kerr's murder and during his funeral. I doubt, however, that the hard hearts of those capable of this act have been dented.
These people operate on the basis of fear and threat; they need us to fear them, so that their threats push us backwards. Back to a time of constant fear, division and terror.
Ronan's death must not be in vain. Being a police officer is a very special thing; you hold a position of trust and you have the potential every day to do something that makes a difference for others.
Stephen Carroll and Ronan Kerr were special, real people from real families who now suffer from very real broken hearts. We owe it to them, their families and to one another to find the courage to do the right thing now.
Our society needs to grasp the initiative and follow the hugely symbolic action and unity demonstrated by our politicians, communities, the GAA and the Police Service.
So do something if and when you can. If you think you know who did this, who helped them, who hides them, or stores their weapons, you must do the right thing and get that information in whatever way you can to your Police Service.