Why is faith so valuable? Thomas Watson answers:

In its being the chief gospel-grace, the head of the graces. As gold among the metals, so is faith among the graces. Clement of Alexandria calls the other graces the daughters of faith. In heaven, love will be the chief grace; but, while we are here, love must give place to faith. Love takes possession of glory, but faith gives a title to it. Love is the crowning grace in heaven, but faith is the conquering grace upon earth. ‘This is the victory that ovecometh the world, even our faith’ (1 John 5:4).

In its being the grace which God honors to justify and save. Thus indeed it is ‘precious faith,’ as the apostle calls it (2 Pet. 1:1). The other graces help to sanctify, but it is faith that justifies. ‘Being justified by faith’ (Rom. 5.1). Repentance or love do not justify, but faith does.