This verse is part of the Upper Room Discourse given by Jesus to his apostles on the night before his sacrificial death. Jesus encouraged his disciples not to let their hearts be troubled although he possibly meant "stop being troubled" (Robert H. Mounce). What would help the disciples of Jesus to avoid becoming faith of heart? His next words provide the answer:
"Trust in God, trust also in me." Moreover, according to Mounce:
Jesus is saying to his disciples, “You do trust in God; therefore trust also in me [pisteuete, “trust,” GK 4409, can be taken as indicative or imperative in either clause]. Have I not yet convinced you that I and my Father are one [10:30; cf. 17: 21– 23]? If the Father is worthy of your trust, so also is the Son.” In light of this, then, Jesus urges, “You must not let yourselves be distressed” (Phillips).
Mounce, Robert H. John (The Expositor's Bible Commentary) (Kindle Locations 6942-6944). Zondervan. Kindle Edition.
Mounce understands the first πιστεύετε to be indicative while he thinks the second πιστεύετε is imperative although he points out that either occurrence of the verb could be indicative or imperative. What difference does the verb's mood make?
Again, quoting Mounce:
The interpretation of v. 1b adopted above takes the first πιστεύετε (pisteuete, GK 4409) as indicative and the second as imperative. Since both can be indicative or imperative in either location (plus the fact that the first may be taken as a question), a rather confusing number of possibilities are available. Jesus is about to be rejected by the nation’s leaders as the promised Messiah, and this event will expose the disciples’ faith to an extreme test. So he encourages them that since they do believe in God they are also to maintain their belief in him, regardless of his coming rejection and death.
Mounce, Robert H.. John (The Expositor's Bible Commentary) (Kindle Locations 7048-7052). Zondervan. Kindle Edition.
Mounce, Robert H.. John (The Expositor's Bible Commentary) (Kindle Locations 7052-7053). Zondervan. Kindle Edition.
W. Harris Hall offers these comments on the grammatical questions in John 14:1
"The translation of the two uses of pisteuete is difficult. Both may be either indicative or imperative, and as Morris points out, this results in a bewildering variety of possibilities.118 To complicate matters further the first may be understood as a question: 'Do you believe in God? Believe also in me.' Morris argues against the AV (KJV) translation which renders the first pisteuete as indicative and the second as imperative on the grounds that for the writer of the Fourth Gospel, faith in Jesus is inseparable from faith in God."
D.A. Carson also discusses the Upper Room Discourse although he calls it, "the Farewell Discourse." One thing I like about Carson's treatment of John 14:1 is that he links Philippians 4:6-7 with the verse: we might also associate Colossians 3:15 in this case. On the other hand, I must offer some critical remarks regarding Carson's exposition of this passage.
Carson believes the indicative/imperative question is "incidental" from one perspective since "in either case Jesus is linking himself directly with God" (page 20). He reckons that John 14:1 constitutes a transparent "claim to deity." His reasoning is that all first-century Jews knew they had to trust in God, but what Jew would put trust in a man the same way that he/she trusted in God (YHWH)? Besides, at some point, a man is going to disappoint us and dash our hopes somehow. But Jesus would never let us down or disappoint us (1 Peter 2:6).
See D.A. Carson, The Farewell Discourse and Final Prayer of Jesus: An Evangelical Exposition of John 14-17. Grand Rapids: Baker Books, 1980; Repackaged Edition published in 2018.
Response: Carson imports large assumptions into his exposition of John 14:1. The verse doesn't exactly declare, "trust in me like you trust in God." Christ just urges his disciples to trust in God and his Son. The verse could be read from the perspective of agency, that is, one could reason that Christ is the agent of God sent to accomplish the divine will. He is the holy one of God (the Messiah), but not necessarily God himself (John 6:69; 17:3). Yes, I'm aware of John 1:1c. But that verse needs to be exegeted with care. Carson and Mounce will not agree, but I see a conceptual parallel between John 14:1 and 2 Chronicles 20:20:
καὶ ὤρθρισαν πρωὶ καὶ ἐξῆλθον εἰς τὴν ἔρημον Θεκωε καὶ ἐν τῷ ἐξελθεῖν ἔστη Ιωσαφατ καὶ ἐβόησεν καὶ εἶπεν ἀκούσατέ μου Ιουδα καὶ οἱ κατοικοῦντες ἐν Ιερουσαλημ ἐμπιστεύσατε ἐν κυρίῳ θεῷ ὑμῶν καὶ ἐμπιστευθήσεσθε ἐμπιστεύσατε ἐν προφήτῃ αὐτοῦ καὶ εὐοδωθήσεσθε (LXX).
Note on Rhetorical Devices:
It appears that John 14:1 employs a rhetorical device. Notice the syntax, πιστεύετε εἰς τὸν θεόν, καὶ εἰς ἐμὲ πιστεύετε.
I might reword the structure like this: "trust in God (A) and in me (B) trust." Observe that "trust" (a verb) begins and ends the clause. We apparently have a chiastic arragement in 14:1 that not only begins and ends with "trust, but uses verbs and prepositional phrases in a rhetorical manner. See https://www.academia.edu/9686371/Chiastic_Structures_in_Hebrews_A_Study_of_Form_and_Function_in_Biblical_Discourse