Have you ever felt that God isn't with you? That when life became tough and darkened God abandoned you? Such a feeling is common to many Christians. However, you must not rely on feelings; instead, you must rely on faith, knowing that God is always there—you just may not always be able to see him in your circumstances. That's why faith is so important.

Hebrews 11:1 defines faith as being sure of what we hope for and certain of what we do not see. For example, if a family member dies, you may understandably question whether or not God could possibly be with you during such difficult times. However, by faith, you can be certain of what [you] do not see—certain that God was there watching over the whole situation.

Romans 4:19-21 describes how Abraham had faith even though it looked like God could never do what he said he would: Without weakening in his faith, he faced the fact that his body was as good as dead—since he was about a hundred years old—and that Sarah's womb was also dead. Yet he did not waver through unbelief regarding the promise of God, but was strengthened in his faith and gave glory to God, being fully persuaded that God had power to do what he had promised.

In his dark circumstances, Abraham could still see God—he had faith. That's the same type of faith to which God is calling you.

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.