Greek word · G1743

ἐνδυναμόω

endynamoō

to empower

Make strong, empower, put power into someone. In the passive: grow strong, be strengthened. The word is rare before the Greek Bible and Christian writings.

Appears 7 times in 7 verses of the Greek New Testament. · Updated October 24, 2026

What it means

ἐν-δυναμόω, -ῶ

[in LXX: Judges 6:34, 1 Chronicles 12:18 A (לָבַשׁ), Psalms 52:7 (עָזַז)* ;]

to make strong, strengthen: with accusative, of person(s), Philippians 4:13, 1 Timothy 1:12, 2 Timothy 4:17. Pass., Acts 9:22; C. dative, Romans 4:20; before ἐν, 2 Timothy 2:1 (ἐν Κυρίῳ), Ephesians 6:10 (Cremer, 221).†

(AS)

From G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922), via STEPBible.org (CC BY 4.0).

In depth

From the study of Philippians 4:13

Range of meaning: Make strong, empower, put power into someone. In the passive: grow strong, be strengthened. The word is rare before the Greek Bible and Christian writings.
Against the English: 'Strengthens' (KJV, ESV) and 'gives me strength' (NIV, BSB) are both accurate. What can be lost is the present tense: this is an ongoing supply, not a single boost.
Used elsewhere in the period: In the LXX: Judges 6:34 in Codex Vaticanus ('the Spirit of the Lord empowered Gideon'), where other manuscripts have 'clothed'. Psalm 51:9 LXX (52:7 in English Bibles), of a man who 'grew strong in his folly'. In Paul's letters: Rom 4:20 (Abraham 'grew strong in faith'), Eph 6:10 ('be strong in the Lord'), 1 Tim 1:12, 2 Tim 2:1, and 2 Tim 4:17 ('the Lord stood by me and strengthened me', said of Paul on trial). Acts 9:22 uses it of Saul 'growing more powerful'.

From the study of Ephesians 6:10

Range of meaning: "To put power into" someone, to strengthen or empower. The passive means "to be made strong" or "to grow strong". It is a rare word, found mostly in Jewish and Christian Greek. In the New Testament God or Christ is always the one who strengthens, or is clearly implied to be (Phil 4:13, "through him who strengthens me"; 1 Tim 1:12; 2 Tim 4:17). The passive is used of people who receive that strength (Rom 4:20, Abraham "was strengthened in faith"; Acts 9:22; 2 Tim 2:1, "be strengthened by the grace that is in Christ Jesus").
Against the English: "Be strong" (KJV, BSB, WEB, NIV, ESV, NASB, NLT) is natural English, but it sounds like an order to act: be tough, summon your strength. The Greek form is almost certainly passive, which is closer to "be strengthened" or "let yourselves be made strong". The Latin Vulgate's confortamini keeps that passive.
How it drifted: The English "be strong" carries the long tradition of the Hebrew "be strong and courageous" (Deut 31:6; Josh 1:6–9), which really is active. In modern use it has also absorbed a self-help ring of personal grit. Both pull the Greek passive toward self-effort.
Used elsewhere in the period: Greek Old Testament (Septuagint): Judg 6:34 (in one manuscript tradition), where the Spirit of the Lord "empowered" Gideon; Ps 51:9 (52:7 in English Bibles), where the wicked man "grew strong" in his own emptiness, a negative use showing the word can describe misplaced sources of strength. It is very rare in non-Jewish Greek before the New Testament. Paul uses it repeatedly of strength given by Christ (BDAG s.v.).

From the study of 2 Timothy 4:17

Range of meaning: "Put power into, make strong, empower." It is a compound of dynamis ("power") with en ("in"), so it means power placed inside a person. The passive means "grow strong" or "be empowered".
Against the English: "Strengthened" (BSB, KJV, ESV, NASB) is fine. NIV's "gave me strength" keeps the sense of a gift. Neither rendering makes clear that the strength is for a task, here speaking at the hearing.
Used elsewhere in the period: The word is rare before the New Testament; it appears in only a few places in the Septuagint (e.g., Ps 51:9 LXX). In the New Testament it is almost entirely Pauline: Rom 4:20; Eph 6:10; Phil 4:13 ("I can do all things through him who strengthens me"); 1 Tim 1:12; 2 Tim 2:1. In Acts 9:22 it describes the newly converted Saul "growing stronger" as he argued that Jesus was the Messiah.

Where it appears

Acts · 1

Acts 9:22 ἐνεδυναμοῦτο was empowered

But Saul was empowered all the more, and he confounded the Jews living in Damascus by proving that Jesus is the Christ.

Here: The tense pictures something going on over time: 'was being made strong', 'kept growing in strength'. The form most naturally reads as passive, so someone else is doing the strengthening. In context that points to God (Saul had just been filled with the Spirit, 9:17), though a middle sense, 'grew strong', is also possible.

Romans · 1

Romans 4:20 ἐνεδυναμώθη was strengthened

Yet he did not waver through disbelief in the promise of God, but was strengthened in his faith and gave glory to God,

Here: Passive: 'was made strong / was empowered'. It may point quietly to God as the one giving strength, or simply mean 'grew strong'. It deliberately contrasts with his body, which was 'as good as dead' (v. 19).

Ephesians · 1

Ephesians 6:10 ἐνδυναμοῦσθε do be empowered

Finally, be strong in the Lord and in His mighty power.

Here: A command addressed to "you" plural, in the present tense and in a form that is almost certainly passive: "keep on being made strong, all of you". The strength comes from outside the readers. They are to let it be given, not to produce it themselves.

Philippians · 1

Philippians 4:13 ἐνδυναμοῦντί strengthening

I can do all things through Christ who gives me strength.

Here: A present participle, so the empowering is continual: 'the one who keeps on putting power into me'. The prefix en- ('in') suggests strength poured into someone.

1 Timothy · 1

1 Timothy 1:12 ἐνδυναμώσαντί having strengthened

I thank Christ Jesus our Lord, who has strengthened me, that He considered me faithful and appointed me to service.

Here: 'The one who put strength into me.' The past (aorist) tense points to a definite empowering, most naturally the one that came with Paul's call and commissioning, not a general boost.

2 Timothy · 2

2 Timothy 2:1 ἐνδυναμοῦ do be strong

You therefore, my child, be strong in the grace that is in Christ Jesus.

Here: A present-tense command in a form that can be read as passive ("be made strong") or middle ("strengthen yourself"). Either way it means an ongoing, repeated strengthening, not a single burst of resolve. Read as passive, as most scholars read it, the strength comes from outside Timothy.
2 Timothy 4:17 ἐνεδυνάμωσέν He strengthened

But the Lord stood by me and strengthened me, so that through me the message would be fully proclaimed, and all the Gentiles would hear it. So I was delivered from the mouth of the lion.

Here: "Put power into me." The point is inner ability to speak boldly at the hearing, not physical rescue. Paul uses the same word in 1 Tim 1:12 for the Lord who empowered him for his calling.

Word data: STEPBible.org (CC BY 4.0), main text only.