This song is one of my all-time favorites and there are a couple of situations in my world that have brought it back to mind. One situation is mine (ours) and the other is mine by association. The lyrics are powerful and at times I don't feel I can even sing it honestly, but I want to. The lines that get me every time are,
"When you call I won't refuse, each new day again I choose"
"When you call I won't delay, this my song through all my days"
That's hard to sing honestly when your personal desires don't line up with what He asks you to do. For me anyway, you might be really awesome and never struggle with that. But the other line that I love is this one...and this is whats important to remember,
"In the moment of my weakness you give me grace to do your will."
He is familiar with our weaknesses, He is mindful that we are but dust, and yet He calls us anyway to do hard, but amazing, things. The beautiful thing is that if we will choose to, at minimum, ask Him to change our desires to match His, then He is at work in us to will and to do His good pleasure. He gives us the grace (which here means empowerment) to do His will - which is why we can say,
"When You call I won't refuse"