Your friend is incorrect (either mislead or dishonest) about what the church teaches. The catholic church has never taught that anyone can be saved by their works. In fact, the catholic church teaches that we are (almost) all unworthy of salvation. More to come on this subject.
and that the Bible teaches Faith = Salvation + Works. What would be the appropriate Catholic response to this?
Your friend is correct that this is what the PROTESTANT sects teach. However he is very incorrect in asserting that this is what the bible teaches. In truth the bible instructs exactly as the catholic position has always been:
Salvation comes only by the Grace of God (not faith)
which COMES THROUGH our faith
and that faith is MADE LIVING by our works.
you’ll clearly notice that your protestant friend has left out entirely the integral concept of grace which is taught by the church and supported by the catholic document known as the bible.
In light of his formula for salvation above, he said that obedience comes as a result of salvation and that we are not called to clean up then come to Christ, but to come to Christ and let Him clean us up.
There is no cleaning of sin EXCEPT through Christ. In other words, he should not be teaching catholic doctrine and then claiming it is not already the churches. The church has held this position for almost 2000 years now.
If I disagree, he wants me to explain Romans 4:5 by answering where obedience comes in to play and what does it mean that God justifies the wicked.
first, when quoting the bible it is polite to put the quote in so we don’t have to look it up. Second of all, your friend does not understand the difference between works of the law and works of christian charity, nor does he understand the motivation behind either.
works of the law are those works prescribed by the pharisees. They were “designed towards salvation” but in truth do nothing for people. As such no matter how many works of the law are done, one is not saved by them. In fact, no action of the self can ever save man. The motivation here is self-salvation… a very BAD motivation.
Works of Christian Charity (what the church teaches) are works that are NOT designed towards salvation. The doer knows that they gain nothing from doing these works except to sacrifice of themselves and thus to make their faith grow. The motivation is not self-salvation, but rather simply to do good for the sake of doing good works. These works complete the soul and make us grow in faith (see the church teaching on salvation by grace through faith made living by works above)
Ultimately, your friend falls prone to a grave error held by MANY protestants: since he lacks any authority or ability to infallibly interpret scriptures he has done a hack job taking romans 4:5 out of context and making it conflict with what the bible clearly teaches in whole. Pray for your friend’s soul and his turning back to the true church in which is kept the TRUE teachings of Christ.