Belief leads to action.
Believing lies and disbelieving God (the Truth - John 14:6) keeps us from right action and guides us to wrong action.
Hebrews 11:31 commends the faith of Rahab who "perished not with them that believed not, when she had received the spies with peace." It is interesting to note that the Greek word for "that believed not" implies disobedience as well as lack of faith. This idea is reinforced by other translations of the verse, such as NASB which simply says "those who were disobedient," or a Spanish version which calls them literally "the disobedient ones."
Haven't you found this connection between sin and disbelief to be true in your own life as well? I certainly have. Generally when I sin, it's simply because I'm not believing God's statements like "...the one who sows to his own flesh will from the flesh reap corruption, but the one who sows to the Spirit will from the Spirit reap eternal life" (Gal. 6:8). I "lose heart in doing good" because I'm not really convinced that "in due time we will reap if we do not grow weary" (Gal. 6:9). Instead of trusting that God "is a Rewarder of those who seek Him" (Heb. 11:6) and taking God's Word for it that "the wages of sin is death" (Rom. 6:23), I rather think that my disobedience is worthwhile. So I sin.
Faith/belief is seriously important, because it protects us from the deadly choice to disobey. So how do we get more faith? "...Faith cometh by hearing, and hearing by the Word of God" (Romans 10:17).
Let's dig into the Word and harvest that life-giving faith. And let's follow God's warning and encouragement in Hebrews 3:12-13. "Take care, brethren, that there not be in any one of you an evil, unbelieving heart that falls away from the living God, but encourage one another day after day, as long as it is still called 'Today,' so that none of you will be hardened by the deceitfulness of sin."
Belief leads to action. Let's believe the Truth.
(For more truth on this subject, consider the following passages. Numbers 20:12; Psalm 78:22, 30-32; Psalm 106:21-24; John 3:18; John 8:24; Hebrews 11:26; Psalm 58:11; Proverbs 11:18; Hebrews 11:1-12:4. Especially Numbers 14:11; Revelation 21:8; Hebrews 3:18-19; Hebrews 4:2,6.)