Allied Foes

There is a very fine line of difference between an ally and a foe,
Until we realise it we won't know.
Both have drastically different definitions,
Yet somewhere along the line they have similar compositions.
Every person is an ally to some and foe to the rest,
He dons whichever role he seems best.
But it's important to have both roles in your pot,
Because one teaches things that the other cannot.
The person whom we call our ally,
Might be our worst foe and that much sly.
Life has a funny way of introducing us to such people with no fret,
Considering the situation, we automatically assume their roles without breaking a sweat.
They accompany us in the life's walk,
While they silently go about with their work in the dark.
We think we know them like the back of our hand,
What we don't know is that their move begins at our wit's end.
We all have allied foes,
It's just a matter of which role's close.