John Wesley on Romans 5:21

That as sin had reigned - so grace also might reign - Which could not reign before the fall; before man had sinned. Through righteousness to eternal life by Jesus Christ our Lord - Here is pointed out the source of all our blessings, the rich and free grace of God. The meritorious cause; not any works of righteousness of man, but the alone merits of our Lord Jesus Christ. The effect or end of all; not only pardon, but life; divine life, leading to glory.