How do we know the doctrine of God is true?

The truth of the doctrine of God is firmly grounded in the Word of God. As Paul states in 2 Timothy 3:16, all Scripture is inspired by God and profitable for teaching, reproof, and instruction in righteousness. The doctrines derived from Scripture are not based on human opinion or tradition, which are often changeable, but on the immutable Word of God. This consistency over time and the unified message across various authors validate the reliability of God's doctrine. Additionally, the miraculous fulfillment of prophecies and the transformational impact of the Gospel throughout history further attest to the truth of God's doctrinal teachings.