Adam Clarke's Bible Commentary Verse 1. Be strong in the grace] Though the genuine import of the word grace is favour, yet it often implies an active principle communicated from God; light directing how to act, and power enabling to act according to the light.
Matthew Henry Commentary
Verses 1-7 - As our trials increase, we need to grow stronger in that which is good our faith stronger, our resolution stronger, our love to God and Chris stronger. This is opposed to our being strong in our own strength. All Christians, but especially ministers, must be faithful to their Captain, and resolute in his cause. The great care of a Christian mus be to please Christ. We are to strive to get the mastery of our lust and corruptions, but we cannot expect the prize unless we observe the laws. We must take care that we do good in a right manner, that ou good may not be spoken evil of. Some who are active, spend their zea about outward forms and doubtful disputations. But those who striv lawfully shall be crowned at last. If we would partake the fruits, we must labour; if we would gain the prize, we must run the race. We mus do the will of God, before we receive the promises, for which reason we have need of patience. Together with our prayers for others, that the Lord would give them understanding in all things, we must exhort an stir them up to consider what they hear or read.
Greek Textus Receptus
συ 4771 P-2NS ουν 3767 CONJ τεκνον 5043 N-VSN μου 3450 P-1GS ενδυναμου 1743 5744 V-PPM-2S εν 1722 PREP τη 3588 T-DSF χαριτι 5485 N-DSF τη 3588 T-DSF εν 1722 PREP χριστω 5547 N-DSM ιησου 2424 N-DSM
Vincent's NT Word Studies
1. Therefore (oun). In view of what has been said in the previous chapter. Be strong (endunamou). In Paul, Rom. iv. 20; Eph. vi. 10; Philippians. iv. 13. Lit. be strengthened inwardly.In the grace (en th cariti). Grace is the inward source of strength. Comp. the association of grace and strength in 2 Cor. xii. 9.
Robertson's NT Word Studies
2:1 {Be strengthened} (endunamou). Present passive imperative of endunamow. See already #1Ti 1:12; Ro 4:20; Php 4:13; Eph 6:10. "Keep on being empowered,"keep in touch with the power." {In the grace that is in Christ Jesus} (en ti cariti ti en Christ"i iesou). Where the power is located. Christ is the dynamo for power only when and while we keep in touch with him.