Is it wrong to speculate or be curious about certain biblical passages if the apostle John warns in Revelations not to add or take away?
John does warn us not to add to Scripture or take away from it (Revelation 22:18). The original context of his warning is for the prophecy of Revelation. But we can extend the context to refer to all of Scripture. His warning is just as true for all of Scripture as it is for the book of Revelation.
However, speculation and curiosity about biblical passages is part of worship to God. As we think about Scripture and try to understand it as best our limited human perspective can handle, we are worshiping God by studying his word.
However, there are questions from faith and questions out of doubt. We must be careful to study the word and consider what it means through questions of faith. If we are asking questions out of doubt, it is not worshiping God. It is questioning his word in a critical manner.
Many volumes have been written about God’s Word. From the many perspectives of different writers concerning the Bible, our own understanding is enhanced. There’s nothing wrong with reading about God’s Word from another human being.
Writing about the Bible does not add to Scripture. It only seeks to understand what has already been written in the Canon of Scripture. We believe that the Canon of Scripture is closed as of 95-96 AD. No more Scripture can be written by anyone. Only the first apostles in the first century had the ability and authority to write Scripture because they had a personal relationship with Jesus while he ministered on the earth.
We may be surprised to find out in heaven those Christians who are there with us. There are many denominations and groups of Christians that believe they are exclusive. They think they’ll be the only ones in heaven. But we will see others we disagree with about scriptural matters in heaven. God is gracious as we seek to understand him.