εις 1519 PREP δε 1161 CONJ την 3588 T-ASF επαγγελιαν 1860 N-ASF του 3588 T-GSM θεου 2316 N-GSM ου 3756 PRT-N διεκριθη 1252 5681 V-API-3S τη 3588 T-DSF απιστια 570 N-DSF αλλ 235 CONJ ενεδυναμωθη 1743 5681 V-API-3S τη 3588 T-DSF πιστει 4102 N-DSF δους 1325 5631 V-2AAP-NSM δοξαν 1391 N-ASF τω 3588 T-DSM θεω 2316 N-DSM
Vincent's NT Word Studies
20. Staggered (diekriqh). Rev., better, wavered. See on Acts xi. 12; Jas. i. 6; ii. 4. The word implies a mental struggle.Promise (epaggelian). See on Acts i. 4.
Was strong (enedunamwqh). Passive voice. Lit., was strengthened, or endued with strength. Rev., waxed strong.
Robertson's NT Word Studies
4:20 {He wavered not through unbelief} (ou diekriqe tei apistiai). First aorist passive indicative of old and common verb diakrinw, to separate, to distinguish between, to decide between, to desert, to dispute, to be divided in one's own mind. this last sense occurs here as in #Mt 21:22; Mr 11:23; Ro 14:23; Jas 1:6. "He was not divided in his mind by unbelief" (instrumental case). {Waxed strong through faith} (enedunam"th ti pistei). First aorist passive again of endunamow, late word to empower, to put power in, in LXX and Paul and #Ac 9:22.