This poem is not saying that god is powerless. Its rationale is biblically based. Following Christ's ascension to heaven he promised to actually come back (in spirit form). The disciples were anguished that he was going and that they would be alone. He said "I will not leave you comfortless, I will come to you" (John 14.18). This, and other texts build the story that Christ is now here on earth in spirit form in the church.
The idea is that he continues his work but does it through the church. So, he used to heal people but now the church 'lays hands on the sick', he preached the gospel now the church does, he spoke words of power and now the church does ('whatsoever you ask in my name ...') etc.
So, this poem is just confirming the story that he has passed his power to the church. It is actually a call to arms for church members - if they don't do the works that he did then his works wont be done. This is a very common theme in evangelical and pentecostal churches.
We can see now that god is not powerless because he has passed his power to his church. Because the church is powerful then he is too. But hold on, I thought that the church was powerless, after all, if they were powerful then they would heal amputees . . . so maybe you're right after all but you've got to understand the middle bit.
Interesting idea, but I have to say not that convincing.
The idea that Jesus is around in spirit form (whatever that means) in the church (es) means that the power he had - healing, bringing back from the dead etc. is now available to the churches to dispense. So, why are the churches not doing just that? I don't mean the silly healing services when people get wound up and then feel better - no, I mean actually curing people from illness and injury. After all, if this power from Jesus is real, we would not need hospitals, the churches would be full and the world would be wonderful.....
Except, it doesn't happen like that and the churches provide nothing that cures people of their illnesses / injuries. For that to happen we have had to create hospitals and medical science. We have had to research and research in order to find out what goes wrong and how to put it right. This work is secular in nature and many of the researchers are not even religious at all, yet we now have all sorts of breakthroughs in medicine that are making our lives longer and better. Explaining how all this works requires science and, importantly, does not have any need for any gods in the process.
Of course, you may mean, keitho1122, that it is looking after the poor and the sick that is the thing Jesus needs people to do but this sort of thing is often being done by the non-religious. The Red Cross was founded as a secular organization for example. So it is a fair bet that the work such as this is being done because of the concern we have as people for others and not in the name of Jesus.
So, keitho1122, tell us - how do we recognise the work of this spirit Jesus and how do we even know that there is a such a thing as a spirit Jesus ( apart from an old book of course.)