The following quote is from Thomas Watson’s book, The Lord’s Prayer:
I shall now answer some doubts and objections that a Christian may make against himself.
I fear the kingdom of grace is not yet come into my heart.
When a Christian is under temptation, or grace lies dormant, he is not fit to be his own judge; but must take the witness of others who have the spirit of discerning. But let us hear a Christian’s objections against himself, why he thinks the kingdom of grace is not yet come into his heart.
I cannot discern grace.
A child of God may have the kingdom of grace in his heart, and yet not know it. The cup was in Benjamin’s sack, though he did not know it was there; so thou mayest have faith in thy heart, the cup may be in thy sack, though thou knowest it not. Old Jacob wept for his son Joseph, when Joseph was alive; so thou mayest weep for want [lack–CD] of grace, when grace may be alive in thy heart. The seed may be in the ground, when we do not see it spring up; so the seed of God may be sown in thy heart, though thou dost not perceive it springing up. Think not grace is lost because it is hid” (Thomas Watson, The Lord’s Prayer, pp. 71-72).
A skillful use of metaphor put to pernicious use. Watson is basically saying that a regenerate child of God may be submitted to a righteousness that he is ignorant of. This is a blatant contradiction to what Paul wrote in Romans 10:3.
For more information on the faith of God’s elect that humbly submits to the righteousness of God revealed in the gospel of Jesus Christ see Marc D. Carpenter’s article, Faith Is Assurance: