God has given me the faith of Christ. I only had to believe; now I have Christ's faith. It would be impossible for me to "willingly walk away" from Christ since God gave me the faith of Christ! He is always faithful! Christ's faith works for me. What works of mine would matter?
Romans 3:22 Even the righteousness of God which is by faith of Jesus Christ unto all and upon all them that believe: for there is no difference:
Galatians 3:22 But the scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe.
Philippians 3:9 And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:
Galatians 2:16 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.
It helps a lot to be able to rightly divide your Bible -- since there are indeed verses that say
someone can lose their salvation. But even without understanding the division, no one today should think that the Faith of Christ could be inadequate once given to them. (The people who can "lose it" aren't given the faith of Christ; they have to live by their own faith.)