Can the man made doctrine of "once saved, always saved" stand against the Old Testament?
The prophet Ezekiel said "And if the virtuous man turns from the path of virtue to do evil, the same kind of abominable things that the wicked man does, can he do this and still live? None of his virtuous deeds shall be remembered, because he has broken faith and committed sin; because of this, he shall die. (Ez 18: 24)"
Jesus agrees with this when He said that "those who persevere to the end shall be saved (Matt 24:13)"
For XY, there are things that we can do that are a sign that we have turned completely away from God. Catholics call this a "mortal sin" John refers to it as a sin that leads to death.
Consider the coldness of a person's heart in the following two situations:
1. If a petition to hire a female lifeguard for a swimming class is successful, the salary for that lifeguard would come out of a budget that would allow me to take a business trip to China. Because I want to go to China, I encourage a talk show host to speak against the petition.
2. Same situation, but I also spread rumors and personally incite hatred against the group that wants the female lifeguard.
3. Same situation, but I cut the brake lines on the car of the person who is heading the petition drive, resulting in her death.
All three of these involve sin, but the hatred in my heart increases and turns me further away from God.
Yes, Mona Lisa, it is called the "No True Scotsman" fallacy and shows why "once saved, always saved" is contrary to Christianity.
Yesmar,
Yes, salvation is by the grace of God. God does not withdraw that grace when we sin. We reject and throw away the gift of salvation when we sin as Ezekiel describes.
Amy,
Foreknowledge and predestination are not the same thing. Yes, being omniscient, God knows who will remain faithful and be saved and who will lose faith and not be saved, but God created each and every person with the intent that everyone be saved.