Believers must test every belief, including long-held notions, and hold fast only to what passes (I Thessalonians 5:21). Many cling tenaciously to Revelation 3:11's command to hold fast while ignoring the instruction to test first. Experience proves that not everything held for decades is true; a Sunday rather than a Monday Pentecost is one example. The only standard is the Bible (Acts 5:29). Human nature is lazy and takes the easy road, relying on human reasoning, the word of others, or tradition rather than the hard, humbling work of studying Scripture and believing what it says. Saying "watch world news" rolls easily off the tongue, but comfort and familiarity do not justify an idea without a solid biblical foundation. The church's history over recent decades shows the fruits of taking doctrine for granted instead of letting clear scriptures guide understanding. People differ on what the Bible says because they come with preconceived ideas, seize any verse that seems to support them, and ignore clear verses that contradict them. God can use this as a test of the heart's true intent: will a person submit humbly to plain instruction, or cling to preconceptions, which are idols? A belief that cannot be proved from clear, unambiguous scriptures should raise a red flag. Clear scriptures form a solid-rock foundation, while ambiguous ones open to private interpretation form a foundation of sand, and only the rock stands when storms come (Matthew 7:24-27). Letting the Bible interpret itself avoids adding extra-biblical meanings.