I was riding the bus to work a few years ago, when I read this remarkable quote:
"All that the Lord hath said will we do, and be obedient." These words (the response of the people with one voice, when Moses had taken the book of the covenant and read in their audience, Exod. 24) were the complete confounding of two very distinct principles, which man has been continually mistaking and confounding since the fall of Adam - responsibility and power. Man is responsible to keep the law perfectly, but by the fall he has lost the power. This the natural heart cannot understand. One man denies his responsibility, and another assumes his power; grace, and this only, puts a man right on both points.(J. N. Darby, "Wilderness Grace", Collected Writings, Vol. 12, p. 276). That was a bit of an "Aha!" moment for me.
Responsibility and power aren't the same thing. It's entirely possible a man (or woman) can be in a position of having a responsibility that he (or she) is incapable of fulfilling. To take an example from secular life, consider the definition of "bankrupt":
any insolvent debtor; a person unable to satisfy any just claims made upon him or her.(bankrupt. (n.d.). Dictionary.com Unabridged. Retrieved September 24, 2013, from Dictionary.com website: http://dictionary.reference.com/browse/bankrupt). So it's possible to end up in a position in the secular world where you cannot "satisfy any just claims".
Even in secular life, responsibility doesn't imply power.
I've listened to a lot of sermons recently combatting "Calvinism". The vast majority of them have argued that it would be unjust of God to demand of someone something that person can't do. They say, "It would be cruel of God to demand sinners repent when they're incapable of repenting". What nonsense.
It's not cruelty for a creditor to demand payment even when the debtor cannot pay. The creditor is looking for nothing more than justice. Similarly, God didn't create us sinful, we made that "improvement" ourselves. He has every right to demand repentance– or even righteousness– of us, whether we can actually produce it or not.
No, I'm not defending "Calvinism", I'm just pointing out that this is a sophomoric and childish argument.
But of course this principle carries on into the Christian walk, even following justification and rebirth. There is a huge difference between responsibility and power. When we look in Scripture, we see there are responsibilities for believers in Christ. We're to walk "worthy of our calling" (Ephesians 4:1). But we find we can't. We have the responsibility, but not the power.
Which is, after all, the whole point of Romans 7.
21 I find then the law upon *me* who will to practise what is right, that with *me* evil is there. 22 For I delight in the law of God according to the inward man: 23 but I see another law in my members, warring in opposition to the law of my mind, and bringing me into captivity to the law of sin which exists in my members. Romans 7:21–23We want to do what's right, and we find ourselves unable to meet our obligations.
What's interesting is how much "ministry" to Christians re-iterates obligations to people who aren't able to meet them. As though enumerating debts can actually enable a bankrupt to pay them! It's foolishness.
The Scriptural path is to look outside myself for power. I can't live up to my calling, but Christ can. I can't overcome the law of sin in my members, but Christ can deliver me.
Obligation doesn't imply the power to fulfill it. That's a lesson that can take a lot of time to learn.