10, 11. (a) What is one important cause of apostasy? (b) What are some parallel meanings of the Greek word translated “to doubt,” and how does the apostate set himself up as a judge?

¹⁰ Among the various causes of apostasy, one of the foremost is unquestionably a lack of faith through doubt. (Heb. 3:12) Interestingly, The New International Dictionary of New Testament Theology supplies the following information on the Greek verb that is often translated by “to doubt”: “Diakrinō, make a distinction, judge, . . . ; doubt, waver. . . . In some [New Testament] passages doubt appears as a lack of faith and thus as sin (Rom. 14:23). . . . In Rom. 4:20f. doubt comes close to disbelief. . . . Doubt is thus a lack of trust in the act of God which he has still to perform and which men are to await. . . . In the NT the doubter sins against God and his promises, because he judges God falsely.”

How to Avoid ‘Falling Away from the Faith’

14, 15. How can we avoid presumptuousness?

¹⁴ We have seen that one of the basic causes of apostasy is a lack of faith through destructive doubt, and that the word translated “doubt” also means “to distinguish.” The apostate makes himself a decider of what is true and what is false, of what is “good and bad” in the way of spiritual food. He becomes presumptuous.​—Compare Genesis 2:17; 3:1-7.

¹⁵ So to avoid falling away from the faith, the Christian should beware of a lack of faith, “the sin that easily entangles us,” and “run with endurance the race that is set before us.” (Heb. 12:1; 3:12, 19) Paul gives us this advice: “Keep testing whether you are in the faith, keep proving what you yourselves are.” (2 Cor. 13:5) Paul is not inviting us to have doubts about “the faith,” but to question ourselves, as to whether we are living up to the faith or not. Such honest self-examination should fill us with modesty and humility, thus protecting us from the independent spirit and presumptuousness of the apostate.

16. (a) What other pitfall should we avoid? (b) What twofold lesson can we learn from the Beroean Jews?

¹⁶ To avoid falling away from the faith, we also need to guard against ingratitude. We should be thankful for the abundant spiritual food we are receiving through the “faithful and discreet slave.” (Matt. 24:45) This does not mean that we should not convince ourselves of things as we go along. In this respect, a twofold lesson can be learned from the Beroean Jews. To be sure, they ‘carefully examined the Scriptures daily as to whether these things were so,’ but they were also “noble-minded” because “they received the word [being preached to them by Paul and Silas] with the greatest eagerness of mind.”​—Acts 17:11.

17, 18. What should we be able to distinguish, and what advice does Paul give on this?

¹⁷ Such grateful eagerness to learn will help us to cultivate love and acquire accurate knowledge, together with full discernment. These Christian qualities will, in turn, enable us to distinguish between things of major importance and those of lesser importance. Is some point we have trouble in understanding really important? Does it affect the truly important things we have learned with the help of the “slave” class? Is it worth stumbling ourselves and perhaps others? Does it prevent us from bearing Christian fruitage?

¹⁸ Paul counsels us: “This is what I continue praying, that your love may abound yet more and more with accurate knowledge and full discernment; that you may make sure of the more important things, so that you may be flawless and not be stumbling others up to the day of Christ, and may be filled with righteous fruit, which is through Jesus Christ, to God’s glory and praise.”​—Phil. 1:9-11.