God alone deserves complete trust for only He can provide fully for our needs. His word calls for a wholehearted response in the form of a surrender of one's self in obedience to His commands. The intellectual element is certainly not lacking in this OT faith, as can be seen in Deuteronomy which contains a primitive Creed that Israel adhered to. But the intellectual content is considerably less prominent than the yielding of the will in submission. Faith is less believing something than belief in the living God.
Faith takes one beyond evidence.
There is, accordingly, a felt risk entailed in the act of faith as is evidenced in the life of Abraham, the Father and model of faith, not only for the Jews but also for Jesus himself and his followers. Our Lord surpassed Abraham's faith but built upon it and absorbed it, as it were, taking it to a more elevated plane to which only he could attain. The Word of God included in his self-emptying at the Incarnation the full human condition which comprises the need to live by faith in God. Jesus' faith was tested to the full when he was rejected by his own people, deserted by his followers and seemingly abandoned by his Father. But he remained obedient and trusting even in death and so became the new model and pattern of faith for his followers.