Annie,
As far as justification and sanctification are concerned, I must first say that you are heading into a discussion that must cover a lot of ground in order to be properly understood and appreciated from each perspective.
Generally, non-catholic Christians believe that Catholics mistakenly don’t distinguish between justification and sanctification and that we frequently use the terms interchangeably. You have to be careful here because, although we properly recognize the differences, we also recognize that both have the same cause(i.e. God’s grace), and that they also happen simultaneously at our spiritual rebirth[see 1 Cor 6:11]. Likewise, both are necessary for salvation.
Furthermore, Catholics recognize that justification is not a one time event. Many non-catholics believe in OSAS which is “once saved always saved.” I can supply you with a considerable amount of scriptural data and a thorough refutation of OSAS if you need it. Just send me a PM with your email and I will send file attachments that will give you everything you need for that one. Likewise, I can supply you with the scriptural references and attendant explanations showing that justification is not a one time event and I will use Abraham as the example. I use Abraham because he is the non-Catholic choice for showing that justification is only a one time event.
For Catholics there is no bright line that completely separates justification and sanctification, but non-catholic Christians do not see it that way. The discussion usually winds up heading into the territory of faith and works and their role or place in salvation. Please keep one thing in mind and use scripture to ground yourself in this. We
do not work our way into heaven. Works are, however, necessary for our salvation. The good works that we do are from God and by his grace and they “complete” our faith and thus also justify per James 2:22-24. Tie that passage from James to Paul’s words in Eph 2:8-10 which says:
Please note all that is in the passage as follows:
- Everything is by grace.
- When God brings us to faith we have done nothing to earn it in any way.
- It is all gift.
- We are God’s workmanship.
- We are as God’s workmanship created in Christ Jesus for good works.
- The good works that we are to do were prepared by the Father even before we are justified.
- As God’s workmanship and by his grace we are to walk in the good works prepared by the Father.
Eph 2:8-10 and James 2 actually explain one another and once you grasp the connections you will be well on your way to properly articulating the Catholic position. There is a whole lot more that can be said on all of this. Besides what you will receive from posters on this thread, I would also recommend the following link:
philvaz.com/apologetics/apolog.htm#SALVATION
I hope this will give you the jump start you need. I will tell you, however, that much preparation is necessary and considerable followup may be needed as well. I’ve only begun to scratch the surface.
God bless.