'Careful' in the Bible

Only be strong and very courageous; be careful to do according to all the law which Moses My servant commanded you; do not turn from it to the right or to the left, so that you may have success wherever you go.

This set of instructions is not to cease being a part of your conversations. Meditate on it day and night, so that you may be careful to carry out everything that's written in it, for then you'll prosper and succeed.

But be careful when you are setting apart the riches for the Lord. If you take any of it, you will make the Israelite camp subject to annihilation and cause a disaster.

Only be very careful to keep the commands and the Law that Moses the servant of the LORD commanded you that is, to love the LORD your God, to follow in all of his ways, to keep his commands, to stay close to him, and to serve him with all your heart and soul."