Greek word · G2901

κραταιόω

krataioō

to strengthen

Active: to make strong, strengthen. Passive: to be strengthened, become strong, prevail. Related to kratos, 'might, power,' a word often used of God's power.

Appears 4 times in 4 verses of the Greek New Testament. ·

What it means

κραταιόω, -ῶ

(late form of κρατύνω; κράτος) [in LXX chiefly for חָזַק ;]

to strengthen; pass., to wax strong: Luke 2:40, 1 Corinthians 16:13; πνεύματι, Luke 1:80; δυνάμει κ. διὰ τ. πνεύματος, Ephesians 3:16.†

(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 1 Corinthians 16:13

Range of meaning

Active: to make strong, strengthen. Passive: to be strengthened, become strong, prevail. Related to kratos, 'might, power,' a word often used of God's power.

Against the English

All the major English versions say 'be strong.' That is fine, but it can sound like 'try hard to be tough.' The passive form allows, and other New Testament uses suggest, 'be made strong' or 'let yourselves be strengthened,' with God as the unstated source.

Used elsewhere in the period

Luke 1:80 and 2:40 (the child John, then Jesus, 'grew and became strong in spirit'); Eph 3:16 ('to be strengthened with power through his Spirit'). In the Septuagint it pairs with ἀνδρίζομαι in Ps 26:14 and 30:25 and in 2 Sam 10:12.

From the study of Judith 1:13

Range of meaning

To make strong; in the passive, to become strong, to prevail, to have the upper hand. Related to κράτος, 'might, dominion'.

Against the English

'Prevailed' (KJV, Brenton, WEB) is accurate. It loses only the sense of process in the passive form: he 'grew strong' over the course of the fighting.

Used elsewhere in the period

In the Septuagint it often renders Hebrew ḥāzaq ('be strong, prevail'), as in 2 Samuel 10:11–12 and 1 Chronicles 19:12. In the New Testament it describes growth in strength (Luke 1:80; 2:40; Ephesians 3:16).

From the study of Luke 1:80

Range of meaning

Krataioō means to make strong or to become strong. It is built on kratos, 'might' or 'ruling strength'. In the Septuagint (the Greek translation of the Hebrew Bible) and in Paul it is usually inner, moral or spiritual firmness rather than muscle. Pneuma covers breath, wind, the human spirit (the inner self that thinks, wills and relates to God) and the Spirit of God. The dative 'in spirit' with no article usually means 'in respect of spirit'.

Against the English

'Became strong in spirit' (BSB, NIV, ESV) is accurate. KJV's 'waxed strong' is archaic: 'wax' simply means 'grow'. English 'spirit' can suggest temperament or morale ('a spirited boy', 'team spirit'), which is thinner than the Greek, where spirit is the self as open to God.

Used elsewhere in the period

Septuagint Psalm 30:25 (31:24 in English Bibles): 'be courageous, and let your heart be strengthened' (krataiousthō). Paul's 1 Corinthians 16:13 uses krataiousthe, 'be strong'. Ephesians 3:16 prays that believers be 'strengthened (krataiōthēnai) through his Spirit in the inner person'. That pairs the same verb with Spirit and the inner self. Luke repeats the formula almost word for word of Jesus in 2:40, 'the child grew and became strong, filled with wisdom'.

Similar words

Where it appears

Luke · 2

  1. Luke 1:80 ἐκραταιοῦτο he was strengthened

    And the child grew and became strong in spirit; and he lived in the wilderness until the time of his public appearance to Israel.

    Here: Imperfect, passive or middle in form: 'was being strengthened' or 'was growing strong'. Read as a passive, it hints that God is the one doing the strengthening. Either way the strengthening goes on over time.

  2. Luke 2:40 ἐκραταιοῦτο He was being strengthened

    And the Child grew and became strong. He was filled with wisdom, and the grace of God was upon Him.

    Here: Imperfect and passive: 'was being made strong', again over a span of time. Without any 'in spirit' (the better text), this means mainly that he grew into a sturdy, healthy child. The passive leaves room for God as the one giving the strength.

1 Corinthians · 1

  1. 1 Corinthians 16:13 κραταιοῦσθε. do be strong.

    Be on the alert. Stand firm in the faith. Be men of courage. Be strong.

    Here: A passive form, 'keep being made strong' or 'grow strong.' Elsewhere in the New Testament this verb describes strength that comes from God or the Spirit (Luke 1:80; 2:40; Eph 3:16). Paired with the previous word, it repeats a familiar Old Testament formula: 'be courageous and be strong.'

Ephesians · 1

  1. Ephesians 3:16 κραταιωθῆναι to be strengthened

    I ask that out of the riches of His glory He may strengthen you with power through His Spirit in your inner being,

    Here: 'To be made strong.' The passive form means God does the strengthening. This is the content of what God is asked to 'give.'

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