How do we know the truth according to the Bible?

Believers have an unction from the Holy One, meaning they possess the indwelling of the Holy Spirit who teaches and guides them into all truth (1 John 2:20). This truth centers on Jesus Christ, who declared himself to be the way, the truth, and the life (John 14:6). The Holy Spirit’s role is crucial, for He reveals the things of Christ to God's people, affirming the foundational truth of their salvation which is rooted in Christ alone. Therefore, knowledge of the truth is not merely intellectual but an intimate relationship with Christ facilitated by the Spirit.