From a recent comment:
How does Christ's work and our faith relate?
What we don’t want to say is that Christ’s sacrifice brings 99 units of salvific merit and my faith brings 1 unit of salvific merit and between His contribution and mine I have accumulated the necessary 100 units.
Even if we say the blood of Christ is 999,999 units and ours is only 1 we have put our faith up where it doesn’t belong. We have made our faith into a work – a contribution towards salvation.
To say “faith alone” is another way of saying “Christ alone” – it is to say our salvation lies entirely outside of us (and therefore outside of our ‘works’). Instead salvation lies entirely in Christ. A ‘faith alone’ person rests in the fact that the blood of Jesus has done everything. But of course we’re not resting in the blood of Jesus alone if we have added our faith into the salvific equation. In that case we would be trusting in “Christ plus our trust.” We then become (to some degree) the objects of our saving faith and not Christ alone!
Let me reiterate. Faith is absolutely essential. A person is not saved if they are not resting in Jesus. But this ‘faith’, this ‘resting in Jesus’ is not our contribution to the equation. It’s a description of what happens when Jesus ’sweeps you off your feet.’ It’s falling in love. It’s being conquered by the gospel.