The idea that both the Bible and the "book of nature" are trustworthy guides is stated in the Belgic Confession.

"Article 2: The Means by Which We Know God

We know him by two means:

First, by the creation, preservation, and government of the universe, since that universe is before our eyes like a beautiful book in which all creatures, great and small, are as letters to make us ponder the invisible things of God: his eternal power and his divinity, as the apostle Paul says in Romans 1:20.

All these things are enough to convict men and to leave them without excuse.

Second, he makes himself known to us more openly by his holy and divine Word, as much as we need in this life, for his glory and for the salvation of his own."

Scriptures that imply that nature is a faithful witness
Biblical encouragement to read the book of nature
Windows of Creation
Evidence from nature Is the universe designed?
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