The beginning of the chapter clearly states that man is dead, and must be made alive by God.Eph 2:1 And you hath he quickened, who were dead in trespasses and sins; There is no way a man that a dead man can live on his own.
Also this verse preceds verses 8,9-Eph 2:5 Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved;)
When we were dead, not when we had faith, but when we were dead.
But coming back to Ephesians, Eph 2:8 For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: The grace mentioned is the animating or life giving force needed to stretch the once dead hand of faith to lay hold on Christ. The faith and the grace do not come from us, but rather are gifts from God Himself.