 He doesn't just zap us into faith as we walk down the street or sit at home watching TV. No, the Holy Spirit gives us faith and he does so through the preaching of the gospel and through the sacraments of baptism and the Lord's Supper. Through these means of grace, the Holy Spirit comes to us as the gospel supplied to us personally. And he plants that faith within us. And the Spirit uses those same means of grace to keep us in that faith.