Is everything replaceable?

They say everything happens for a reason, 

I didn’t believe,

You made me believe.

I didn’t have a brother,

You became the one.

How can I portray you?

When I turn the pages of my life,

On each page I find a picture of you

I was in dark,

You showed me the light.

I was wandering,

You showed me the path.

The hill was steep to climb,

You pulled me up.

I was confused,

Your guidance made me go through.

I was longing for a support,

You stood up like a wall.

They say everything is replaceable,

But who will replace you?