Owen on Justification:

3dly. The examples of them that did believe, and were justified,
which are recorded in the Scripture, do all bear witness unto the
same truth. The continuation of the justification of Abraham before
God is declared to have been by faith only, Rom.4:3; for the
instance of his justification, given by the apostle from Gen.15:6,
was long after he was justified absolutely. And if our first
justification, and the continuation of it, did not depend absolutely
on the same cause, the instance of the one could not be produced for
a proof of the way and means of the other, as here they are. And
David, when a justified believer, not only places the blessedness of
man in the free remission of sins, in opposition unto his own works
in general, Rom.4:6,7, but, in his own particular case, ascribes the
continuation of his justification and acceptation before God unto
grace, mercy, and forgiveness alone; which are no otherwise received
but by faith, Ps.130:3-5; 143:2. All other works and duties of
obedience do accompany faith in the continuation of our justified
estate, as necessary effects and fruits of it, but not as causes,
means, or conditions, whereon that effect is suspended. It is
patient waiting by faith that brings in the full accomplishment of
the promises, Heb.6:12,15. Wherefore, there is but one
justification, and that of one kind only, wherein we are concerned
in this disputation,--the Scripture makes mention of no more; and
that is the justification of an ungodly person by faith. Nor shall
we admit of the consideration of any other. For if there be a second
justification, it must be of the same kind with the first, or of
another;--if it be of the same kind, then the same person is often
justified with the same kind of justification, or at least more than
once; and so on just reason ought to be often baptized;--if it be
not of the same kind, then the same person is justified before God
with two sorts of justification; of both which the Scripture is
utterly silent. And [so] the continuation of our justification
depends solely on the same causes with our justification itself.


The mercy of God is necessary not only when a person repents, but even to lead him to repent, Augustine