How is Paine able to use his personal experience in the army to help make his case in The Crisis?

Paine's experience as an officer in the army allowed to
give credence and credibility to his writing.  Through his experience in the army, he
was able to listen to the narratives of those around him.  It is clear that he
understood the fears and doubts of his fellow soldier.  In being able to move freely
between ranks and intermingle with different soldiers from different backgrounds, Paine
was able to offer up a level of commitment and strength to his words.  This helped out
with his message.  When Paine writes about the struggle and the insecurity as well as
the questioning of the cause, he is able to not speak his own voice, but rather the
voices of the soldiers that are around him.  This directly speaks to their own fears,
and in the process allows them to listen clearly to what Paine has to say.  Paine
understood that his fundamental purpose in writing the pamphlet was to inspire the men
fighting for the Colonial cause.  In an astute manner, Paine grasped that in order to
motivate, one has to directly speak.  His experience as a solider afforded him a direct
line of communication with those who were listening to and reading his
words.

I think that
Paine's time as a soldier helps to underscore his points and increase his credibility
with his audience in the writing of The Crisis in a couple of ways.  The first would be
that Paine understands what the soldiers are enduring.  Being a soldier along with them,
he recognizes the formidable British threat and how the early phases of the war were not
going well for the Colonists.  He is not writing in a vacuum.  He is writing of
experience and in doing so, brings credibility with his words as the soldiers, his
audience, understand that it is one of their own who is writing and speaking to them. 
At the same time, Paine understands that the soldiers are facing a "crisis" in terms of
Washington as their leader.  In his writing, there is an absolute affirmation of
Washington's leadership, something that resonates clearly with soldiers.  In assuming
the voice of a soldier seeking to inspire his fellow troops, Paine's writing triggers in
those intangible elements for which the Colonists fight.  Through speaking as a soldier
to an audience of soldiers, Paine's words have greater and added effect in its
resonance.