Then why does God not provide the perseverance of faith to those believers who fall away into unbelief and are still saved according to you?
Actually, God DOES provide lifelong faith to His children.
Galatians 2:16 KJV
16) Knowing that a man is not justified by the works of the law, but
by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be
justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified.
1 Peter 1:3-5 KJV
3) Blessed be the God and Father of our Lord Jesus Christ, which according to his abundant mercy hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead,
4) To an inheritance incorruptible, and undefiled, and that fadeth not away, reserved in heaven for you,
5)
Who are kept by the power of God through faith unto salvation ready to be revealed in the last time.
God's power keeps us by supplying our faith, and that is how God can be so certain that we will actually receive the inheritance that He has reserved for us. His power in us is our faith to believe.
The faith of Jesus Christ.
Not your faith.
The faith of Jesus Christ.
Galatians 2:19-21 KJV
19) For I through the law am dead to the law, that I might live unto God.
20) I am crucified with Christ: nevertheless I live;
yet not I, but Christ liveth in me: and the life which I now live in the flesh
I live by the faith of the Son of God, who loved me, and gave himself for me.
21) I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain.
Frustrate . . . in my interlinear is translated, Repudiate. Do not repudiate the grace of God, It's not about what you do, it's about what He did.
Much love!