Mark 5:36

5:36 But Jesus, paying no attention to what was said, told the synagogue ruler, “Do not be afraid; just believe.”

Mark 9:23-24

9:23 Then Jesus said to him, “‘If you are able?’ ¹  All things are possible for the one who believes.” 9:24 Immediately the father of the boy cried out and said, “I believe; help my unbelief!”

Mark 11:31

11:31 They discussed with one another, saying, “If we say, ‘From heaven,’ he will say, ‘Then why did you not believe him?’

Mark 13:21

13:21 Then ²  if anyone says to you, ‘Look, here is the Christ!’ ³  or ‘Look, there he is!’ do not believe him.

Mark 16:17

16:17 These signs will accompany those who believe: In my name they will drive out demons; they will speak in new languages; ⁴ 

[9:23]  ¹ tc Most mss (A C³ Ψ 33 Ï) have τὸ εἰ δύνασαι πιστεῦσαι (to ei dunasai pisteusai, “if you are able to believe”), instead of τὸ εἰ δύνῃ (to ei dunh, “if you are able”; supported by א B C* L N* Δ Ë¹ 579 892 pc). Others have εἰ δύνῃ (or δυνάσαι) πιστεῦσαι (“if you are able to believe”; so D K Θ Ë¹³ 28 565 al), while still others have τοῦτο εἰ δύνῃ (touto ei dunh, “if you can [do] this”; so [Ì⁴⁵] W). The reading that best explains the rise of the others is τὸ εἰ δύνῃ. The neuter article indicates that the Lord is now quoting the boy’s father who, in v. 22, says εἴ τι δύνῃ (ei ti dunh, “if you are able to do anything”). The article is thus used anaphorically (see ExSyn 238). However, scribes could easily have overlooked this idiom and would consequently read τὸ εἰ δύνῃ as the protasis of a conditional clause of the Lord’s statement. As such, it would almost demand the infinitive πιστεῦσαι, producing the reading τὸ εἰ δύνασαι πιστεῦσαι (“if you are able to believe, all things are possible…”). But the article here seems to be meaningless, prompting other scribes to modify the text still further. Some dropped the nonsensical article, while others turned it into the demonstrative τοῦτο and dropped the infinitive. It is clear that scribes had difficulty with the original wording here, and made adjustments in various directions. What might not be so clear is the exact genealogy of the descent of all the readings. However, τὸ εἰ δύνῃ is both a hard saying, best explains the rise of the other readings, and is supported by the best witnesses. It thus rightly deserves to be considered authentic.

[13:21]  ¹ tn Here καί (kai) has been translated as “then” to indicate the implied sequence of events within the narrative.

[13:21]  ² tn Or “the Messiah”; both “Christ” (Greek) and “Messiah” (Hebrew and Aramaic) mean “one who has been anointed.”

[16:17]  ¹ tn Grk “tongues,” though the word is used figuratively (perhaps as a metonymy of cause for effect). To “speak in tongues” meant to “speak in a foreign language,” though one that was new to the one speaking it and therefore due to supernatural causes. For a discussion concerning whether such was a human language, heavenly language, or merely ecstatic utterance, see BDAG 201-2 s.v. γλῶσσα 2, 3; BDAG 399 s.v. ἕτερος 2; L&N 33.2-4; ExSyn 698; C. M. Robeck Jr., “Tongues,” DPL, 939-43.