This then is what the apostle means by the "Power of Christ's resurrection," and this is what we are as much concerned experimentally to know, as that He rose at all.
Without this, though we may be moralists, though we may be civilized, good-natured people, yet we are no Christians. For he is not a true Christian, who is only one outwardly; nor have we therefore a right, because we daily profess to believe that Christ rose again the third day from the dead. But he is a true Christian who is one inwardly; and then only can we be stiled true believers, when we not only profess to believe, but have felt the power of our blessed Lord's rising from the dead, by being quickened and raised by his Spirit, when dead in trespasses and sins, to a thorough newness both of heart and life.
The devils themselves cannot but believe the doctrine of the resurrection, and tremble; but yet they continue devils, because the benefits of this resurrection have not been applied to them, nor have they received a renovating power from it, to change and put off their diabolical nature. And so, unless we not only profess to know, but also feel that Christ is risen indeed, by being born again from above, we shall be as far from the kingdom of God as they: our faith will be as ineffectual as the faith of devils.
- George Whitefield
The Power of Christ's Resurrection