What is the The theme of the young warrior by James Weldon Johnson

I personally believe its about how he is going to war and is praying he comes back home to his mother. This is the poem - Mother, shed no mournful tears,

But gird me on my sword;

And give no utterance to thy fears,

But bless me with thy word.

The lines are drawn! The fight is on!

A cause is to be won!

Mother, look not so white and wan;

Give Godspeed to thy son.

Now let thine eyes my way pursue

Where'er my footsteps fare;

And when they lead beyond thy view,

Send after me a prayer.

But pray not to defend from harm,

Nor danger to dispel;

Pray, rather, that with steadfast arm

I fight the battle well.

Pray, mother of mine, that I always keep

My heart and purpose strong,

My sword unsullied and ready to leap

Unsheathed against the wrong.