“For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; not as a result of works, that no one should boast” (Eph.2:8-9). Some bible students (especially extreme Calvinists) take the “it” in Eph. 2:8 to refer to faith - that even saving faith is a gift of God. Grace and faith also are part of the total package of salvation which is the gift of God. The antecedent of “it is the gift of God” is the salvation by grace through faith. “It”(touto) is neuter in form and cannot refer to faith (pistis) which is feminine.
The best commentary on this passage is given by the great NT Greek scholar, A.T.Robertson. “‘Grace’ is God’s part, ‘faith’ ours. And that [it] (kai touto). Neuter, not feminine taute, and so refers not to pistis [faith] or to charis [grace] (feminine also), but to the act of being saved by grace conditioned on faith on our part” (Word Pictures in the New Testament, 4:525).
Salvation is the gift of God. Salvation is through faith, not because of faith. Faith is not the cause of salvation; faith is only the channel through which we receive the gift of salvation. Man can never boast of anything in relation to his salvation.