Does that sound unsound?

Two good friends of mine recently picked out the song "Look What You've Done," by Tree63 as being theologically unsound.

Here are the lines in question:

"It's not a question of what you can do for me
But what can I do for you my Lord?"

I have spent the day since wondering what is so unsound about it?
Here's the rest of the lyrics, if you're interested:

Look what you've done for me
Your blood has set me free
Jesus my Lord look what you've done for me

I haven't been the same
Ever since that day I called your name
Yahweh Yahweh look what you've done for me

What can I do for you my Lord?
I want you to know my heart is yours
It's not a question of what you can do for me
But what can I do for you my Lord?

Up to your cross I crawl
Now I am standing ten feet tall
Jesus my saviour look what you've done for me

Free at last I'm free
I owe you my life completely
Yahweh Yahweh look what you've done for me

Am I missing something? Are they missing something? I honestly don't know. Someone shed some light on this for me.