# G4100 - pisteuo **Strong's:** [G4100](https://www.blueletterbible.org/lexicon/g4100/) · BLB lookup **Pronunciation:** pist-yoo'-o **Part of speech:** verb **Root:** from [G4102 - pistis](/codex/g4102-pistis/) (πίστις, "faith / trust") **NT occurrences:** ~244 ## Semantic range (Thayer / BDAG) 1. **To think to be true, to be persuaded of, to credit**, intellectual assent; agreeing that a proposition is true. 2. **To trust, to have confidence in, to entrust oneself to**, relational; staking oneself on something or someone. 3. **In Johannine usage especially: to commit oneself to Christ in saving faith**, the comprehensive sense involving knowledge, assent, and trust (*notitia, assensus, fiducia* in Reformation theology). ## Theological force The verb's grammatical construction in NT Greek does theological work: - **πιστεύω + dative**, to believe a person, accept their testimony as true (*pisteuō tinī*). - **πιστεύω + ὅτι (hoti)**, to believe that something is the case (propositional belief). - **πιστεύω + εἰς (eis) + accusative**, *to believe into*, to commit oneself to, place trust in, transfer allegiance to. **This is John's signature construction for saving faith.** ([John 3.16](/codex/john-3-16/) *πᾶς ὁ πιστεύων εἰς αὐτόν*; [John 3:18](/codex/john-3-18/); [1 John 5:13](/codex/1-john-5-13/).) The shift from *believing that* to *believing into* is the difference between intellectual assent and personal commitment. [James 2:19](/codex/james-2-19/) ("the demons also believe, and shudder") shows that *pisteuō* in the propositional sense alone does not save, even demons grasp the truth of monotheism. Saving faith (*pisteuō eis*) is committed trust, not bare assent. This construction underwrites the Reformation doctrine of *sola fide*, salvation through faith alone, where "faith" is not mere belief-that but trust-in. The Roman Catholic and Reformed traditions agree on the threefold structure of saving faith: knowledge (*notitia*), assent (*assensus*), and trust (*fiducia*); the difference is over the *role* of faith (instrument of justification vs initiating sacrament). ## Notable verses ### Saving faith, *pisteuō eis* - **[John 3.16](/codex/john-3-16/)**, "whoever believes (*pisteuōn eis*) in Him shall not perish but have eternal life" - **[John 3:18](/codex/john-3-18/)**, "He who believes in Him is not judged" - **[John 3:36](/codex/john-3-36/)**, "He who believes in the Son has eternal life" - **[John 6:29](/codex/john-6-29/)**, "this is the work of God, that you believe in Him whom He has sent" - **[John 11:25-26](/codex/john-11-25-26/)**, "everyone who lives and believes in Me will never die" - **[John 14:1](/codex/john-14-1/)**, "believe in God, believe also in Me" - **[Acts 16:31](/codex/acts-16-31/)**, "believe in the Lord Jesus, and you will be saved" - **[Romans 10:9-10](/codex/romans-10-9-10/)**, "if you believe in your heart that God raised Him from the dead" ### Propositional belief, *pisteuō hoti* - **[John 11:27](/codex/john-11-27/)**, "I have believed that You are the Christ, the Son of God" - **[John 16:30](/codex/john-16-30/)**, "by this we believe that You came from God" - **[John 17:21](/codex/john-17-21/)**, "that the world may believe that You sent Me" - **[Hebrews 11:6](/codex/hebrews-11-6/)**, "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" ### Believing testimony / a person, *pisteuō* + dative - **[John 5:46](/codex/john-5-46/)**, "if you believed Moses, you would believe Me" - **[John 5:24](/codex/john-5-24/)**, "he who… believes Him who sent Me" - **[Acts 8:12](/codex/acts-8-12/)**, "believed Philip preaching the good news" - **[1 John 4:1](/codex/1-john-4-1/)**, "do not believe every spirit" ### Faith as the work / opposite of unbelief - **[John 6:29](/codex/john-6-29/)**, "the work of God: believe in Him whom He has sent" - **[Mark 9:24](/codex/mark-9-24/)**, "I do believe; help my unbelief" - **[John 20:27](/codex/john-20-27/)**, "do not be unbelieving, but believing" - **[John 20:29](/codex/john-20-29/)**, "blessed are they who did not see, and yet believed" ### Demonic assent, non-saving "belief" - **[James 2:19](/codex/james-2-19/)**, "the demons also believe, and shudder", propositional belief is not saving faith - **[James 2:14-26](/codex/james-2-14-26/)**, "what use is it… if someone says he has faith but he has no works?" ## Connection to OT, *aman* / faith of Abraham [Genesis 15:6](/codex/genesis-15-6/): "Abraham believed (LXX: *episteusen*) the LORD, and He reckoned it to him as righteousness." This verse is foundational for Pauline theology of justification by faith ([Romans 4](/codex/romans-4/); [Galatians 3](/codex/galatians-3/)). The Hebrew root *aman* (H539), root of "amen", combines reliability and trust. The LXX renders it with *pisteuō*, locking in the linguistic bridge from Hebrew faith to Greek-NT faith. ## Patristic / scholarly note Augustine (*De Trinitate* 13.2; *Tractates on John*) develops the threefold structure of faith: *credere Deo* (believe God, assent to His testimony), *credere Deum* (believe that God *exists*, propositional), *credere in Deum* (believe *into* God, wholehearted trust). Only the third is saving. Aquinas (*ST* II-II, q.2, a.2) systematizes this into *fides informis* (mere intellectual assent) vs *fides formata* (faith formed by love, the saving kind). The Reformation pressed *fiducia* (trust) as the heart of saving faith against medieval scholastic emphasis on *assensus*. Luther's *Bondage of the Will* (1525) and Calvin's *Institutes* III.2 treat *pisteuō* as the receptive instrument of justification, the empty hand that grasps Christ's righteousness. ## Verses in this codex _See Obsidian's backlinks pane for every verse page linking here._ Top-cited references using *pisteuō*: [John 3.16](/codex/john-3-16/), [Romans 10.13](/codex/romans-10-13/) (closely related construction), [John 1.14](/codex/john-1-14/) (paired with monogenēs). ## See also - [G4102 - pistis](/codex/g4102-pistis/), the noun "faith" - [H0539 - aman](/codex/h0539-aman/), Hebrew "to confirm / believe / trust" - [G5485 - charis](/codex/g5485-charis/), "grace", paired with faith in [Eph 2:8-9](/codex/ephesians-2-8-9/) - [G1344 - dikaioo](/codex/g1344-dikaioo/), "to justify", the result of faith