God has given us His Word as a guide for our life. However, His Word won't help us if we don't study it, know it, and live by it. Therefore, we must diligently study and apply God's Word if we wish for it to have an impact on our lives.

Jesus promised, "If you abide in My word ..., you are truly My disciples. And you will know the Truth, and the Truth will set you free" (John 8:31-32, AMP). That's a promise that if we abide in His Word, we will know the Truth, because His Word is the Truth.

So it makes sense that God told the Israelites, "Do not let this Book of the Law depart from your mouth; meditate on it day and night, so that you may be careful to do everything written in it. Then you will be prosperous and successful" (Joshua 1:8).

Joshua later repeated a similar instruction: "Be careful to obey all that is written in the Book of the Law of Moses, without turning aside to the right or to the left" (Joshua 23:6).

Why is it so important to follow God's Word? Because His Word keeps us from turning aside to the right or to the left; it keeps us on the straight and narrow path that leads to life (see Matthew 7:13-14).

Therefore, abide in His Word, because His Word will keep you from sin.

There are far too many Christians who live two different lives: one on the inside, another on the outside; one Sunday morning, another the rest of the week.

Such people are hypocrites, phonies, Christian liars; they live wrong lives. Why? Because they have a wrong heart. We must be very careful that our heart is clean and pure (see Psalm 51:10).

We are told in Matthew 12:34 why our heart is so important: For out of the overflow of the heart the mouth speaks. In other words, your heart affects your mouth.

Since our lives, and especially our words, are being examined by unbelievers, we must be careful to have a clean heart so that we will have clean words; and if we have clean words, then our lives will show good fruit. In other words, a good (spiritual) heart will bear good fruit.

No good tree bears bad fruit, nor does a bad tree bear good fruit. Each tree is recognized by its own fruit. People do not pick figs from thornbushes, or grapes from briers. The good man brings good things out of the good stored up in his heart, and the evil man brings evil things out of the evil stored up in his heart. For out of the overflow of his heart his mouth speaks (Luke 6:43-45).

Therefore, be careful that your words are clean and pure and that your actions are equally clean and pure so that the world will see that your life matches your lip.