The contemporary English word “faith” is derived from the Latin word fides. It denotes trust and in today’s modern language means “to believe.” “Faithfulness” denotes trustworthiness or dependability in today’s English language. Being faithful is a Biblical concept. The Holman Illustrated Bible Dictionary says of faithfulness,
Throughout the Scriptures faith is the trustful human response to God’s self-revelation via His words and His actions.(1)
Because God initiates the relationship between Himself and us, His expectation is that we would trust Him. By not trusting Him, we in turn commit sin just as our first father and mother–Adam and Eve–did in the Garden of Eden (Genesis 3:1-7). Yet, in His infinite wisdom, God continues to act and do what is necessary for us in our limited knowledge of Him to bring us to a place of trusting Him. He continues to reveal Himself to us through His Word, the Bible, and by His Holy Spirit continues to help us to “fix our eyes on Jesus Christ, the Author and Perfecter of our faith” (Hebrews 12:1-3).
God’s Word in the Old Testament
Throughout the Bible, God helps us to understand what it means to be faithful. A significant word in the Old Testament Hebrew, aman, a root word, denotes “reliability, stability, and firmness.” It means in its explicit form “to support” or “to uphold,” for example, the strong arms of a parent would uphold an infant. A faithful father would hold his child in his arms to keep him from harm, and his holding would be sure, certain, and firm. God encourages man to live in trusting Him in Deuteronomy 7:9-11:
Know therefore that the LORD your God, He is God, the faithful God, who keeps His covenant and His lovingkindness to a thousandth generation with those who love Him and keep His commandments; but repays those who hate Him to their faces, to destroy them; He will not delay with him who hates Him, He will repay him to his face. Therefore, you shall keep the commandment and the statutes and the judgments which I am commanding you today, to do them.
Psalm 119 teaches us that God’s Word–or words–are reliable, constant, and faithful. It is through His Word that we are enabled to possess objective virtues, faithfulness and reliability.
Another Hebrew word, yare’, used to convey the idea of faith, is usually translated “to fear.” This word occurs more often in the Old Testament than aman and expresses very similar concepts. To “fear God” is to
To fear God is to believe Him with a reverential awe, even to the point that emotional trepidation occurs. To fear Him is to maintain a firm conviction that the Lord’s directives are reliable, protective, and beneficial to the believer.
Read how the psalmist speaks of what it means to fear God:
Forever, O LORD, Your word is settled in heaven. Your faithfulness continues throughout all generations; You established the earth, and it stands. They stand this day according to Your ordinances, for all things are Your servants. (Psalm 119:89-91)
Behold, the eye of the LORD is on those who fear Him, on those who hope for His lovingkindness, to deliver their soul from death and to keep them alive in famine. (Psalm 33:18-19)
How great is Your goodness, which You have stored up for those who fear You, which You have wrought for those who take refuge in You, before the sons of men! (Psalm 31:19)
When a person knows God in an intimate way, he dreads disappointing Him, but the outcome of the fear of the Lord is joy and complete satisfaction. The writer of Ecclesiastes says,
The conclusion, when all has been heard, is: fear God and keep His commandments, because this applies to every person. (Ecclesiastes 12:13)
Old Testament writers used “the fear of the LORD” to underscore the importance of submission to God through what He has revealed.Our minds, wills, and emotions–because we trust God–should be submissive to His will. When we submit ourselves to God then our behavior reflects God’s character of faithfulness.
God is always faithful and He exemplifies His faithfulness in His Word, the Bible. For instance, God predicted that He would make an everlasting covenant through which he would enable people to fear him forever.
I will make an everlasting covenant with them that I will not turn away from them, to do them good; and i will put the fear of Me in their hearts so that they will not turn away from Me. (Jeremiah 32:40)
God even says that He will write His law on the hearts of His people and allow them to know Him personally.
“But this is the covenant which I will make with the house of Israel after those days,” declares the LORD, “I will put My law within them and on their heart I will write it; and I will be their God, and they shall be My people. They will not teach again, each man his neighbor and each man his brother, saying, ‘Know the LORD,’ for they will all know Me, from the least of them to the greatest of them,” declares the LORD, “for I will forgive their iniquity, and their sin I will remember no more.” (Jeremiah 31:33-34)
The way that God describes what He will do for His people is incredible: God will help us through His faithfulness to know Him personally. This helps us and empowers us to know Him and to please Him through our faithfulness to Him. The prophet Habakkuk said it this way:
Behold, as for the proud one, his soul is not right within him; but the righteous will live by faith. (Habakkuk 2:4)
God’s Word in the New Testament
The New Testament word for “faith” that is used more frequently than any other is the Greek word pistis.
It conveys the idea of trust, a firm internal conviction regarding the truthfulness of someone or some claim. The verb form, pisteuo, is usually translated, “I believe” or “I trust.” Pistis and pisteuo in the NT correspond to the OT terms aman and yareʾ. Pistis also appears in the NT with the definite article to describe particular Christian beliefs, termed “the faith.”
Many of the New Testament writers appropriate and show the continuity of “faith” and “faithfulness” from the Old Testament to the New Testament. For instance, Paul the apostle uses Abram’s faithfulness to God as a model for how God continues to save “by faith” in Romans 4. In Romans 1:17 Paul also quotes Habakkuk when he writes:
For in it the righteousness of God is revealed from faith to faith; as it is written,”But the righteous man shall live by faith.”
Also in Galatians 3:11 Paul writes:
Now that no one is justified by the Law before God is evident; for, “The righteous man shall live by faith.”
Just as it was true in the Old Testament that prior to Jesus Christ’s coming, it is impossible after His first coming for someone without faith to please God.
And without faith it is impossible to please Him, for he who comes to God must believe that He is and that He is a rewarder of those who seek Him. (Hebrews 11:6)
God’s self-revelation has increased dramatically through the Person and Work of Jesus Christ. His life, ministry, death, burial, and resurrection are God’s verbal and active self-revelation and is the perfect means by which one may know God and His faithfulness to man.
This is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent. (John 17:3)
It is through Jesus Christ that God the Father has communicated His love, His justice, and HIs mercy. Moreover, it is through these events that God has declared Jesus Christ to be His unique Son and His love for us. Read, again, how Paul the apostle says this:
But God demonstrates His own love toward us, in that while we were yet sinners, Christ died for us. (Romans 5:8)
God’s faithfulness continues in His written word and through the teaching and preaching of His people. John the apostle writes:
Therefore many other signs Jesus also performed in the presence of the disciples, which are not written in this book; but these have been written so that you may believe that Jesus is the Christ, the Son of God; and that believing you may have life in His name. (John 20:30-31)
In every generation God makes His faithfulness known. And in turn, this causes us to grow in our faithfulness to Him. This “faith” that we have, this “faith” that we know is what was taught by the prophets and apostles. And when we continue to follow this faith in God, in His Son, Jesus Christ, and in His Word, then addition to the church continues.
The word of God kept on spreading; and the number of the disciples continued to increase greatly in Jerusalem, and a great many of the priests were becoming obedient to the faith. (Acts 6:7)
After they had preached the gospel to that city and had made many disciples, they returned to Lystra and to Iconium and to Antioch, strengthening the souls of the disciples, encouraging them to continue in the faith, and saying, “Through many tribulations we must enter the kingdom of God.” (Acts 14:21-22)
I was still unknown by sight to the churches of Judea which were in Christ; but only, they kept hearing, “He who once persecuted us is now preaching the faith which he once tried to destroy.” (Galatians 1:22-23)
But now that faith has come, we are no longer under a tutor. (Galatians 3:25)
(1) Much of this article is adapted from: D. Mark Parks, “Faith, Faithfulness,” ed. Chad Brand et al., Holman Illustrated Bible Dictionary (Nashville, TN: Holman Bible Publishers, 2003), 547-551.