Contradiction with Matthew 24:35
This verse states, "Heaven and earth shall pass away, but my words shall not pass away," suggesting an eternal certainty of divine words, which can be viewed as contrasting with the need to "take heed" due to a lack of clarity or permanence implied in 2 Peter 1:19.
Matthew 24:35: Heaven and earth shall pass away, but my words shall not pass away.
Contradiction with 1 Corinthians 2:14
This verse implies that the natural man cannot understand the things of the Spirit of God. The contradiction arises in that 2 Peter 1:19 assumes the capacity to heed prophecy.
1 Corinthians 2:14: But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know [them], because they are spiritually discerned.
Contradiction with 1 Timothy 6:16
This states that God "dwelleth in the light which no man can approach unto," implying God's word is inherently understandable only through divine revelation, unlike the "more sure" word of prophecy in 2 Peter 1:19.
1 Timothy 6:16: Who only hath immortality, dwelling in the light which no man can approach unto; whom no man hath seen, nor can see: to whom [be] honour and power everlasting. Amen.