i REALLY like this, it's actually very good...just a few things.
in the chorus, i would change it from Who am I that You choose me to 'who am i that You chose me'-make it past tense.
also i would make it "eternal life IS a guarantee", add the 'is.'
then you put "set our here to rescue me." i tried and tried to think of what you meant to say, but i couldn't figure it out, LOL. so yeah, if you could say what you meant to put that would help
other than that, it's really good. i especially love the ending. good job!!