Take time to thoroughly understand why the Arminian influenced basis and method used by this organization does not faithfully represent Scripture.
It's more than just not liking the organization or its approach.
The Apostle Paul said that even when the gospel was preached with false motives, he rejoiced (cf Phil. 1:15).
Thankfully, one does not have to understand deeper systems of doctrine in order to be saved. No doubt God uses wrong methods, and even the presentation of wrong biblical implications. There was good fruit in the life and death of the founder of this organization, and I have no reason to doubt he was a believer.
The zeal, though wrong in focus, (e.g. decisionism) does challenge and put many of us to shame. That's I would tend to encourage, not discourage a new believer who was in this.
But, I would also engage them. It's a serious thing to misrepresent God, and how He sovereignly saves. But that is something that comes with maturity, the gentle reproof and correction of the Word.
Post Tenebras Lux; "And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away." - Revelation 21:4