Jude 1:3 …contend earnestly for the faith which was once for all delivered to the saints
Jesus called a person who hears the word and understands it as good ground or good soil, (Mat 13:23). Understanding is special revelation. The natural revelation is important and most necessary as is the law, only scripture has superior power to bring to light special revelation.
Dreams and visions can awaken and lead to seeking to know, but of themselves they have no power to save, 2Pet 1:19-21 “19 And so we have the prophetic word confirmed, which you do well to heed as a light that shines in a dark place, until the day dawns and the morning star rises in your hearts 20 knowing this first, that no prophecy of Scripture is of any private interpretation, 21 for prophecy never came by the will of man, but holy men of God spoke as they were moved by the Holy Spirit.” (NKJV). Peter here says we have a more sure word and Jude encourages believers to stick to word that was once for all delivered to the saints, that is preaching the gospel.