Be strong and courageous, for you shall cause this people to inherit the land that I swore to their fathers to give them. Only be strong and very courageous, being careful to do according to all the law that Moses my servant commanded you. Do not turn from it to the right hand or to the left, that you may have good success wherever you go. This Book of the Law shall not depart from your mouth, but you shall meditate on it day and night, so that you may be careful to do according to all that is written in it. For then you will make your way prosperous, and then you will have good success. (Joshua 1:6-8 ESV)
Carefulness is a theme in the book of Joshua (1:7, 8; 22:3-5; 23:11). Some of the problems the Israelites faced were due to carelessness on their part, for example, the failed attack on Ai, and the Gibeonite deception. The word used in Joshua for being careful means to “keep, watch, guard, or protect”. It is the same word used in Genesis 2:15 for the command given to Adam to “guard” or “protect” the Garden of Eden.
This word is used in the OT for tending a flock, protecting property, or keeping watch over a city. Throughout the Bible there are repeated calls to believers to be careful, to stay alert, to be watchful. The opposite of this is to be careless, distracted, and forgetful about the things of God.
Carefulness involves “not turning to the right hand or to the left” (1:7), that is, keeping focus on God’s path for us and walking faithfully in his ways. Sometimes, when driving on the road with my family, I’ll point out some of the scenery I notice. My family always reminds me, “You drive. We’ll look at the scenery.” In other words, keep your eyes on the road.
Carefulness in biblical teaching involves meditation upon God’s Word, which is concentrated, continual thought upon biblical truth. It involves meditating upon it “day and night” (Josh. 1:8) This is Christian meditation.
Carefulness is similar to, but not identical to, what today is termed, “mindfulness.” It is similar in that we are concentrating and having greater awareness. Both involve keeping focus. In today’s world this is more of a technique, of being aware of one’s own body, sensations, and thoughts. An article in Psychology Today states, “Mindfulness is a state of active, open attention on the present. When you’re mindful, you carefully observe your thoughts and feelings without judging them good or bad. Instead of letting your life pass you by, mindfulness means living in the moment and awakening to your current experience, rather than dwelling on the past or anticipating the future.” (psychologytoday.com/basics/mindfulness)
But “carefulness” (and meditation) from a biblical perspective is more about content than technique. It is more outward (God-ward) rather than inward (breathing or sensations). It involves past, present, and future, from God’s perspective. It involves focused thought and careful attention to what God has authoritatively revealed in his Word.
The call to carefulness is echoed in the New Testament, as well. The Apostle Paul called upon believers to “look carefully then how you walk, not as unwise but as wise…”, “keep watch on yourself… be on the alert...” (Eph. 5:15; 6:1, 18), and “continue steadfastly in prayer, being watchful in it with thanksgiving” (Col. 4:2). The Lord Jesus, in teaching his disciples to be prepared for his return, said, “Be on guard, keep awake...” (Mark 13:33) and “watch yourselves lest your hearts be weighed down… stay awake...” (Luke 21:34, 36).
This is also why church leaders, specifically elders (pastors / overseers) are to “keep watch over your souls” (Heb. 13:17), especially, in guarding the church from false teaching (Acts 20:28-31). Every false teaching which the church faces is a temptation to “turn to the right or to the left” from God’s word and ways.