justified freely - without anything done on our part to deserve.
by his grace - His free love.
through the redemption that is in Christ Jesus - a most important clause; teaching us that though justification is quite gratuitous, it is not a mere fiat of the divine will, but based on a “Redemption,” that is, “the payment of a Ransom,” in Christ’s death. That this is the sense of the word “redemption,” when applied to Christ’s death, will appear clear to any impartial student of the passages where it occurs.