Flavel on Justification

How dangerous it is to join anything of our own to the righteousness of Christ, in pursuit of justification before God! Jesus Christ will never endure this; it reflects upon His work dishonorably. He will be all, or none, in our justification. If He has finished the work, what need is there of our additions? And if not, to what purpose are they? Can we finish that which Christ Himself could not complete? Did He finish the work, and will He ever divide the glory and praise of it with us? No, no; Christ is no half-Savior.
It is a hard thing to bring proud hearts to rest upon Christ for righteousness. God humbles the proud by calling sinners wholly from their own righteousness to Christ for their justification.
- John Flavel