I have never understood this position. If you have received Christ as Savior because you placed your faith in Him and believed Him to be true, how do stop believing in the truth?No one can take our faith, but we can choose to reject God, even after first accepting him.
It's like saying I know my name is Amy. It's on my birth certificate. That's the truth and I know it and accept it. But today I've decided to reject that fact, even though I know my name is Amy. That makes no sense.
If you know something to be true, how do stop believing it's true? It would have to be proven to you that what you believed was true is now false. If you believe Jesus is true (the way the truth and the life), there is nothing that can prove Him to be false, because He IS truth and you know it through the Holy Spirit who indwells you and is a witness to this truth.
If you really have believed in Christ and have received His salvation and Holy Spirit, you cannot stop believing. It would be illogical and insane.