Hebrews 12:2 "Looking unto Jesus the author and finisher of our faith; who for the joy that was set before him endured the cross, despising the shame, and is set down at the right hand of the throne of God."
"What some say of rooted faith, fides radicata, that it continues, while weak faith may come to nothing, seems to be contradicted by this Scripture; for, as the strongest faith may be shaken, so the weakest, where truth is, is so far rooted that it will prevail. Weakness with watchfulness will stand, when strength with too much confidence fails. Weakness, with acknowledgement of it, is the fittest seat and subject for God to perfect his strength in; for consciousness of our infirmities drives us out of ourselves to him in whom our strength lies.
From this it follows that weakness may be consistent with the assurance of salvation. The disciples, notwithstanding all their weaknesses, are bidden to rejoice that their names are written in heaven. Failings, with conflict, in sanctification should not weaken the peace of our justification and assurance of salvation. It matters not so much what ill is in us, as what good; not what corruptions, but how we regard them; not what our particular failings are so much as what the thread and tenor of our lives are, for Christ's dislike of that which is amiss in us turns not to the hatred of our persons but to the victorious subduing of all our infirmities." —Richard Sibbes (1577-1635)
Excertp taken from The Bruised Reed, The Banner of Truth Trust. First published 1630, revised edition 1998. p. 96