1-е Петра 1:21

by him--Compare "the faith which is by Him," Act 3:16. Through Christ: His Spirit, obtained for us in His resurrection and ascension, enabling us to believe. This verse excludes all who do not "by Him believe in God," and includes all of every age and clime that do. Literally, "are believers in God." "To believe IN (Greek, 'eis') God" expresses an internal trust: "by believing to love God, going INTO Him, and cleaving to Him, incorporated into His members. By this faith the ungodly is justified, so that thenceforth faith itself begins to work by love" [P. LOMBARD]. To believe ON (Greek, "epi," or dative case) God expresses the confidence, which grounds itself on God, reposing on Him. "Faith IN (Greek, 'en') His blood" (Rom 3:25) implies that His blood is the element IN which faith has its proper and abiding place. Compare with this verse, Act 20:21, "Repentance toward (Greek, 'eis,' 'into,' turning towards and going into) God and faith toward (Greek, 'eis,' 'into') Christ": where, as there is but one article to both repentance and faith, the two are inseparably joined as together forming one truth; where "repentance" is, there "faith" is; when one knows God the Father spiritually, then he must know the Son by whom alone we can come to the Father. In Christ we have life: if we have not the doctrine of Christ, we have not God. The only living way to God is through Christ and His sacrifice. that raised him--The raising of Jesus by God is the special ground of our "believing": (1) because by it God declared openly His acceptance of Him as our righteous substitute; (2) because by it and His glorification He received power, namely, the Holy Spirit, to impart to His elect "faith": the same power enabling us to believe as raised Him from the dead. Our faith must not only be IN…

The apostle describes the persons to whom he writes, and salutes them (Pe1 1:1, Pe1 1:2), blesses God for their regeneration to a lively hope of eternal salvation (Pe1 1:3-5), in the hope of this salvation he shows they had great cause of rejoicing, though for a little while they were in heaviness and affliction, for the trial of their faith, which would produce joy unspeakable and full of glory (Pe1 1:6-9). This is that salvation which the ancient prophets foretold and the angels desire to look into (Pe1 1:10-12). He exhorts them to sobriety and holiness, which he presses from the consideration of the blood of Jesus, the invaluable price of man's redemption (Pe1 1:13-21), and to brotherly love, from the consideration of their regeneration, and the excellency of their spiritual state (Pe1 1:22-25).