That phrase is a reference to the Bible and that it is absolute truth. Absolute truth means truth that is always right…regardless of the circumstances…regardless of the situation, it is absolute…always right.
But many people don’t believe in absolute truth. Instead, they believe in situation ethics which teaches that a given situation will determine how a decision is made. This is the opposite of absolute truth.
Isaiah 40:8 says, “The grass withers, the flower fades, But the word of our God stands forever.”
God’s word is absolute. It will never mislead us. Our world is more governed by situation ethics than absolute truth and it has led us into moral and ethical chaos.
But, someone may say, “the Bible is old. It’s out of date.” The Bible says that it is “…living and active and sharper than any two-edged sword.”
God’s word is inspired. It is authoritative. I encourage you to build your life on God’s word, which is absolute truth.