Gospel Guidebook: Getting and Keeping It Right 
Equivalent Meaning of "Believe" Expressions
by Robert P. TerryUpdated July 6, 2026
In this article, I will attempt to show that the expressions "to believe" (πιστεύειν), "to believe that" (πιστεύειν ὅτι), and "to believe in" (πιστεύειν εἰς) are used equivalently. I will do this by examining the biblical data, especially in the Gospel of John and the First Epistle of John.
(UPDATE: Several months after writing this article, I learned that the Rudolf Bultmann came to a similar conclusion regarding these phrases on page 203 of Volume 6 of the Theological Dictionary of the New Testament. He wrote, "Particularly distinctive is the common πιστεύειν εἰς (→ II, 432, 31 ff.) in the sense "to believe in," which is neither Gk. nor LXX.220 This can hardly be regarded as a development of πιστεύειν c. dat. == "to trust." On the contrary, πιστεύειν c. dat. is used more after the analogy of πιστεύειν εἰς for "to believe in." The fact that πιστεύειν εἰς is equivalent to πιστεύειν ὅτι shows rather that πιστεύειν εἰς arises out of the use of πιστεύειν for "to regard as credible, as true." πιστεύειν εἰς Χριστὸν Ἰησοῦν (Gl. 2:16), εἰς αὐτόν and εἰς ἐμέ (often in Jn.) etc. simply means πιστεύειν ὅτι Ἰησοῦς ἀπέθανεν καὶ ἀνέστη … (1 Th. 4:14; cf. R. 10:9) or ὅτι Ἰησοῦς ἐστιν ὁ χριστός (Jn. 20:31) etc. In Jn. esp. πιστεύειν εἰς and πιστεύειν ὅτι are constantly used interchangeably in the same sense." END)
As an initial observation, we see that πιστεύειν + a noun in the dative case (e.g., to believe him) is equated with πιστεύειν + the preposition εἰς + the noun in the accusative case (e.g., to believe in him) in John 6:29-30 and John 8:30-31. Also, we see the reverse in John 14:11-12 and Romans 4:3-5.
John 6:29-30 ἀπεκρίθη ὁ Ἰησοῦς καὶ εἶπεν αὐτοῖς, Τοῦτό ἐστι τὸ ἔργον τοῦ Θεοῦ, ἵνα πιστεύσητε εἰς ὃν ἀπέστειλεν ἐκεῖνος (you believe in him whom he has sent). εἶπον οὖν αὐτῷ, Τί οὖν ποιεῖς σὺ σημεῖον, ἵνα ἴδωμεν καὶ πιστεύσωμέν σοι (we may believe you); τί ἐργάζῃ;
John 8:30-31 ταῦτα αὐτοῦ λαλοῦντος πολλοὶ ἐπίστευσαν εἰς αὐτόν (they believed in him). Ἔλεγεν οὖν ὁ Ἰησοῦς πρὸς τοὺς πεπιστευκότας αὐτῷ (them having believed him) Ἰουδαίους, Ἐὰν ὑμεῖς μείνητε ἐν τῷ λόγῳ τῷ ἐμῷ, ἀληθῶς μαθηταί μου ἐστέ·
John 14:11-12 πιστεύετέ μοι (believe me) ὅτι ἐγὼ ἐν τῷ πατρί, καὶ ὁ πατὴρ ἐν ἐμοί· εἰ δὲ μή, διὰ τὰ ἔργα αὐτὰ πιστεύετέ μοι (believe me). ἀμὴν ἀμὴν λέγω ὑμῖν, ὁ πιστεύων εἰς ἐμέ (the one who believes in me), τὰ ἔργα ἃ ἐγὼ ποιῶ κἀκεῖνος ποιήσει, καὶ μείζονα τούτων ποιήσει· ὅτι ἐγὼ πρὸς τὸν πατέρα μου πορεύομαι.
Romans 4:3-5 τί γὰρ ἡ γραφὴ λέγει; Ἐπίστευσε δὲ Ἀβραὰμ τῷ Θεῷ (he believed God), καὶ ἐλογίσθη αὐτῷ εἰς δικαιοσύνην. τῷ δὲ ἐργαζομένῳ ὁ μισθὸς οὐ λογίζεται κατὰ χάριν, ἀλλὰ κατὰ τὸ ὀφείλημα. τῷ δὲ μὴ ἐργαζομένῳ, πιστεύοντι δὲ ἐπὶ τὸν δικαιοῦντα τὸν ἀσεβῆ (the one who believes on the one justifying the ungodly), λογίζεται ἡ πίστις αὐτοῦ εἰς δικαιοσύνην.
In addition to the above, we also see that the usage in John 6:47 is equivalent to that in John 5:24.
John 5:24 ἀμὴν ἀμὴν λέγω ὑμῖν ὅτι ὁ τὸν λόγον μου ἀκούων, καὶ πιστεύων τῷ πέμψαντί με, ἔχει ζωὴν αἰώνιον·(the one who believes the one who sent me has eternal life) καὶ εἰς κρίσιν οὐκ ἔρχεται, ἀλλὰ μεταβέβηκεν ἐκ τοῦ θανάτου εἰς τὴν ζωήν.
John 6:47 ἀμὴν ἀμὴν λέγω ὑμῖν, ὁ πιστεύων εἰς ἐμὲ, ἔχει ζωὴν αἰώνιον. (the one who believes in me has eternal life)
Let's now take a look at 1 John 5:9-10 because I think this passage is highly relevant to this discussion.
9 εἰ τὴν μαρτυρίαν τῶν ἀνθρώπων λαμβάνομεν, ἡ μαρτυρία τοῦ Θεοῦ μείζων ἐστίν· ὅτι αὕτη ἐστὶν ἡ μαρτυρία τοῦ Θεοῦ, ἥν μεμαρτύρηκε περὶ τοῦ υἱοῦ αὐτοῦ. 10 ὁ πιστεύων εἰς τὸν υἱὸν τοῦ Θεοῦ (the one who believes in the Son of God) ἔχει τὴν μαρτυρίαν ἐν ἑαυτῷ· ὁ μὴ πιστεύων τῷ Θεῷ (the one who does not believe God), ψεύστην πεποίηκεν αὐτόν, ὅτι οὐ πεπίστευκεν εἰς τὴν μαρτυρίαν (the one who has not believed in the testimony), ἣν μεμαρτύρηκεν ὁ Θεὸς περὶ τοῦ υἱοῦ αὐτοῦ.
In these verses we see that the main issue at hand is believing God's testimony. John compares receiving God's testimony to receiving a man's testimony. They entail the same passive act of accepting a proposition as being true, with the exception that God's testimony is much more authoritative. "Believing in the Son of God" equates to "having the testimony in oneself" (i.e., "believing in the Son of God" = "believing testimony about the Son of God"). What's more is that we find "believing in the Son of God" (with the preposition), "believing God" (without the preposition), and "believing in the testimony" (with the preposition) placed in very close proximity with each. "Believing in the testimony" follows the exact pattern of πιστεύειν + the preposition εἰς + a noun in the accusative case, and for all practical purposes, is semantically equivalent to "believing testimony" without the preposition. It seems that for the Apostle John, the presence or absence of the preposition in "believe" expressions had no significant meaning, if any at all.