The number forty appears most frequently in the Old Testament and often (not always) connects to incidents of judgment, testing, or preparation. Though numerology is intriguing, reading the Bible should focus more on understanding its truths than figuring out secret meanings in numbers.
The Bible often (but not always) uses forty in the context of judgement, testing, or preparation. By far, this occurs more frequently in the Old Testament than the New. Some key examples of forty in the Old Testament that fit the themes of judgement and testing are the number of days it rained during the flood (Genesis 7:12), the forty years the Israelites wandered in the wilderness (Numbers 14:33-34; Deuteronomy 8:2-5), and the forty days that Goliath taunted the Israelite army before being defeated by David (1 Samuel 17:16). The New Testament account of Jesus being tempted by Satan in the desert for forty days fits the "preparation" theme. But other references in the New Testament do not fit that or other associated themes or are incidental (Acts 1:3; 2 Corinthians 11:24). While noting patterns of numbers in Scripture (numerology) can be intriguing, it's unwise to attribute a symbolic meaning to every use of a common number. Even when the number forty is symbolic, that doesn't mean it isn't also literal. And sometimes, forty is just forty without any extra layer of meaning. Ultimately, what matters is the wisdom God has given us through His Word.
People notice patterns. To a gambler, that number he keeps seeing becomes his “lucky” number. He’ll bet that at roulette or play it in the lottery. Wins confirm his belief while any losses are vagaries of the environment (“That woman next to me was wearing an orange shirt—an unlucky color for me!”). But this is problematic. Treating coincidence as meaning and feelings as fact does not ground us in reality.
The same is true with numerology. There is a danger in applying numerology to Scripture. Some numbers are repeated in Scripture, but we should never force meaning onto a passage simply because a common number appears in it. If we do, we turn the Bible into something mystical and manipulatable rather than what it claims to be: the holy, inspired Word of God. In doing so, we unintentionally drift into treating it like a code to crack instead of a message to receive.
Reading Scripture can involve noticing patterns, but those patterns should never outrun the text itself or replace its clear meaning. The goal is not to hunt for hidden signals in numbers but to hear God’s voice in the words He has actually given. What matters most is not what we think we can extract from the structure but what God has already revealed through it.