The Israelites failed to enter into their rest. Many years later (Ps. 95), God said that a rest was still available. That “today” is still here! This means that Joshua did not lead Israel into the true rest, because a rest still remains. (Note that the name “Jesus” in Heb. 4:8, KJV, ought to be “Joshua.” “Jesus” is the Greek form of “Joshua.”). The “therefore” in verse 6 makes it clear that the statements of verses 6–7 are derived from the previous quotes of verses 4–5.
Three thoughts are evident from verses 6-7. First, God intends for some people to enter the promised rest. If the Jews did not enter the rest, someone else must enter it, or God’s promise of experiencing rest would be void and empty. Second, the first generation stumbled because of their disobedience or unbelief. Third, God’s offer of rest is still open as shown by a repeated quotation of Psalm 95:7b–8a. The word “Today” emphasizes that God’s invitation to enjoy rest with Him finds fulfillment in the present.