The following is from Session 6 of the Council of Trent, where Catholic doctrine and dogma on justification were laid down in broader and clearer fashion than had ever been done before, as an answer to the claims of the Reformers 500 or so years ago of which your Baptist friend is a direct theological descendant:
CHAPTER IX
AGAINST THE VAIN CONFIDENCE OF HERETICS
But though it is necessary to believe that sins neither are remitted nor ever have been remitted except gratuitously by divine mercy for Christ’s sake, yet it must not be said that sins are forgiven or have been forgiven to anyone who boasts of his confidence and certainty of the remission of his sins,[47] resting on that alone, though among heretics and schismatics this vain and ungodly confidence may be and in our troubled times indeed is found and preached with untiring fury against the Catholic Church.
Moreover, it must not be maintained, that they who are truly justified must needs, without any doubt whatever, convince themselves that they are justified, and that no one is absolved from sins and justified except he that believes with certainty that he is absolved and justified,[48] and that absolution and justification are effected by this faith alone, as if he who does not believe this, doubts the promises of God and the efficacy of the death and resurrection of Christ.
For as no pious person ought to doubt the mercy of God, the merit of Christ and the virtue and efficacy of the sacraments, so each one, when he considers himself and his own weakness and indisposition, may have fear and apprehension concerning his own grace, since no one can know with the certainty of faith, which cannot be subject to error, that he has obtained the grace of God.
