Pistis is used in II Thessalonians 2: 13-14, "But we are bound to give thanks alway to God for you, brethren beloved of the Lord, because God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief of the truth: Whereunto he called you by our gospel, to the obtaining of the glory of our Lord Jesus Christ." In II Thessalonians 2: 13 belief is from the Greek word pistis. In Strong's Exhaustive Concordance number 4102, pistis, from number 3982, peitho, "to convince, to assent, agree, assume, believe, have confidence,obey, trust, yield." Then for the definition of 4102, pistis, Strong's says the word means "persuasion, i.e., credence, conviction of truth, especially reliance on Christ for salvation, assurance, belief, faith, fidelity."
In a great many verses in the Gospel of John Strong's number 4100 is used, pisteuo, meaning "to have faith...to entrust, especially one's spiritual well being to Christ, believe, put trust in."
Then, in the New Testament other than in John's Gospel, faith is from the Greek word pistis, Strong's number 4102, defined above.
So, to believe the word of God, to assent to it, obey it, to have a conviction of its truth, and to trust Christ for your salvation, is the same as having faith.
Man in the spiritual state of the natural man does not discern that which is spiritual (I Corinthians 2: 14). He may discern that which is of the flesh, of his heart and mind.
To have faith, to believe the word of God, and to see it as absolute truth which cannot be comprmized by man's reasoning, is given to us by God.
"For it is God which worketh in you both to will and to do of his good pleasure." Philippians 2: 13
In the compartmentalized world of the II Timothy 3: 5, 7-8 churches faith might be said tgo be different from the gift of God in the form of belief in and acceptance of the doctrines of scripture - because this gift from God implies some amount of change, or transformation in a person, and the II Timothy 3: 5, 7-8 churches do not want to go there.
"Having a form of godliness, but denying the power thereof: from such turn away.,
7. Ever learning, and never able to come to the knowledge of the truth.
8. Now as Jannes and Jambres withstood Moses, so do these also resist the truth: men of corrupt minds, reprobate concerning the faith." II Timothy 3: 5, 7-9
Having only a form, or appearance of godliness, never able to come to the knowledge of the truth and resisting the truth are outcomes of not being born again, or transformed in Christ, by those of the II Timothy 3: 5, 7-8 churches