As an agnostic, I will simply quote the following:
SUMMARY OF CATHOLIC TEACHING
1. God knows all things, including those who will be saved (THE ELECT).
2. God's foreknowledge does not destroy, but includes, free will.
3. God desires all men to be saved.
4. Jesus died to redeem all men.
5. God provides sufficient grace for all men to be saved.
6. Man, in the exercise of his free will, can accept or reject grace.
7. Those who accept grace are saved, or born-again.
8. Those who are born-again can fall away or fall into sin.
9. Not everyone who is saved will persevere in grace.
10. Those who do persevere are God's elect.
11. Those who do not persevere, or who never accepted grace, are the reprobate.
12. Since we can always reject God in this life, we have no absolute assurance that we will persevere.
13. We can have a moral assurance of salvation if we maintain faith and keep God's commandments (1 John 2:1-6; 3:19-23; 5:1-3,13).
IMPORTANT DISTINCTIONS
1.
Predestination is not predetermination
2. Election is a consequence of God's foreknowledge
3.
Free will can resist and reject God's grace
http://www.bringyou.to/apologetics/num21.htm