Nicky Gumbel says we should think of it like this: The value of a cheque depends not only on the amount, but also on the name that appears at the bottom. If I wrote out a cheque for ten million pounds it would be worthless; but if Bill Gates, reputed to be the richest man in the world, were to write a cheque for ten million pounds it would be worth exactly that. When we go to the bank of heaven we have nothing deposited there. If I go in my own name I can achieve nothing; but Jesus Christ has unlimited credit in heaven. He has given me the privilege of using his name.
Nicky Gumbel, Alpha Questions of Life, 2007 edition, Eastbourne: Kingsway Communications, p.70