You just continue to fabricate your own definitions. Belief doesn't secure salvation, Christ did this. Faith is evidence of conversion, not the cause nor the sustainer, and it is God's gift, we believe by His power; Ephesians 1:19. Your efforts are to incessantly supplant Christ with man.
More fabrications. OSAS hase never taught that a person must __________ to maintain salvation. You're being dishonest.
And you're incorrect about h-grace saying you do not have to continue to believe, that error was brought in via Lewis Sperry Chafer, and Zane Hodges, popularized in Free Grace Theology well prior to hg. And they are both as wrong as you are - only a true convert will persevere in belief unto the end. You continue to misunderstand and misapply 1 Corinthians 15:1-2. You're stuck on that passage, like a cultist one-verse gotcha. To believe in vain is to not truly have believed:
Here is Gill on this, predecessor to Surgeon. Note, as being a proponent of osas, he doesn't believe the "traditional osas" lie that Phart is attempting to push on everyone. What Phart is saying then is untrue, unsubstantiated error:
unless ye have believed in vain: not that true faith can be in vain; for that is the faith of God's elect, the gift of his grace, the operation of his Spirit; Christ is the author and finisher of it, and will never suffer it to fail; it will certainly issue in everlasting salvation: but then as the word may be heard in vain, as it is by such who are compared to the wayside, and to the thorny and rocky ground; and as the Gospel of the grace of God may be received in vain; so a mere historical faith may be in vain; this a man may have, and not the grace of God, and so be nothing; with this he may believe for a while, and then drop it: and since each of these might possibly be the case of some in this church, the apostle puts in these exceptions, in order to awaken the attention of them all to this important doctrine he was reminding them of.
H. A. Ironside: (Phart will concentrate only on the last statement and take it out of context, like he does with Scripture)
Through this gospel the Corinthians had been saved-if their faith was genuine. If their faith was not real, Paul said, they had “believed in vain.” He was not intimating that some who had believed the gospel might be lost at last; rather he was saying that continuance in the faith was the evidence of the genuineness of their faith. This is important. Christ said, “He that endureth to the end shall be saved”
Pulpit Commentary: (read the entire thing, get yourself past the "If ye" part and get to the understanding part. Many know what Scripture says, but miss what it means, thus Phart's errors)
(4) by means of which they were now in a state of safety, they were of the class of sozomenoi (Act_2:47). If ye keep in memory what I preached unto you. The order, which is peculiar, is, "In what words I preached to you, if ye hold [it] fast." Possibly the "in what discourse" depends on "I make known to you." The duty of "holding fast" what they had heard is often impressed on the early converts (1Co_11:2; 2Co_6:10; 1Th_5:21; Heb_10:23). Ye have believed; rather, ye believed; i.e. ye became believers. In vain. The word may either mean "rashly," "without evidence," as in classical Greek; or "to no purpose," "without effect," as in Rom_13:4; Gal_3:4; Gal_4:11. In this case they would have received the seed in stony places (Mat_13:21).