Jesus saves, faith does not.

Jesus is the "agent" of salvation. Faith is the "instrument" of salvation. We must not confuse the two.

Jesus is the agent who accomplishes all saving graces for us and in us. Jesus "saves," "justifies," "sanctifies," and "glorifies" his people in fulfillment of his Father's sovereign purpose and by means of the Spirit's power. His name is "Jesus" because he saves his people from their sins (Matt 1.21).

Faith is the instrument that receives Jesus the savior (John 1.12). Faith is the weak and helpless means whereby Jesus grants his saving blessings to poor and miserable sinners like you and me (Rom 4.16-21). Faith isn't the obedience that Jesus demands when we've fallen short of his more difficult demands. Faith is an alternative to Jesus' demands (Rom 4.4-5). To be sure, faith is the root from which all grateful obedience to Jesus flows (Gal 5.6). But Jesus is the soil that nourishes this root and the life-giving water that causes it to bear fruit (Eph 3.17). 

When faith becomes the agent of salvation, we run into serious problems. We start wondering if and when we truly believed, and if we are believing strongly enough, sincerely enough, consistently enough. 

When Jesus becomes the instrument of salvation, we run into serious problems as well. Rather than trusting him to complete the good work he initiated in us (Phil 1.6), and to watch over his Word to perform it (Jer 1.12), we start thinking of him as a passive spectator to our salvation, someone we need to manipulate through pious activities so that he'll wake up and give us what we need, or what we think we need.

Jesus and faith go hand in hand. But they do so in a definite order and relation. Confuse that order and relation and you--as well as those who overhear your confusion--will have serious spiritual problems. Get that order right and you'll start thinking and talking a lot more about Jesus and his saving deeds and a lot less about faith. And that's a good thing: because Jesus is a spectacular savior and he alone--not our faith--is worthy of our trust.