Jonathan Edwards on the necessary effects of true belief:
“So if men are really convinced of the things they hear in the gospel about an eternal world and that everlasting salvation which Christ has purchased, it will influence their practice; they will regulate their behavior according to such a belief; they will act so as tends to their obtaining this eternal salvation.
If men are convinced of the certain truth of the promises of the gospel, which promise eternal riches and honor and pleasure, that they are immensely better than all the riches and honors and pleasures of this world, if they will forsake the things of the world and sell all and follow Christ, if they are fully convinced of the truth of these promises, viz. that Christ will bestow such things which are so much better and of so much long continuance, if this appears real to them, it will have influence upon their practice; it will induce them to sell al to follow Christ; they will actually do it in their practice.
The nature of men will not allow them to do otherwise.
If a man be promised by another that if he will part with one pound he will give him a thousand, and he is fully convinced of the truth of his promise, and is fully satisfied that the thousand pounds will be a thousand times better to him upon all accounts than that one pound, he will part with that one pound.
So he that is convinced of the sufficiency of Christ to deliver him from all evil, and to bring him to the possession of all good which he needs, if he be truly convinced, it will have influence on his practice.
Such a man, while he actually has such conviction, will not be afraid to cleave to Christ in thing in which he otherwise would seem greatly to expose himself to great calamity; for he is convinced that Christ is sufficient to deliver him.
So he will not be afraid to forego other ways of seeking happiness, because he is convinced that Christ alone is sufficient to bestow all needed happiness.”
May God be gracious to us that we may live according to the truth we have received in Christ.
From Charity and Its Fruits, Sermon 10, “Grace Tends to Holy Practice.” In Ethical Writings, vol. 8 of The Works of Jonathan Edwards, ed. Paul Ramsey (New Haven: Yale University Press, 1989), 300.