D&C 67

What the Lord said to some brethren in conference, I consider to be to all -

"Behold and hearken, O ye elders of my church, who have assembled yourselves together, whose prayers I have heard, and whose hearts I know, and whose desires have come up before me"   (Doctrine and Covenants 67:1)

With that, He also said -

"Ye endeavored to believe that ye should receive the blessing which was offered unto you; but behold, verily I say unto you there were fears in your hearts, and verily this is the reason that ye did not receive."  (Doctrine and Covenants 67:3)

I don't have any idea what this blessing was, but it does suggest that "fears in our hearts" may limit our faith.

What I found instructive to me is -

"...verily I say unto you that it is your privilege, and a promise I give unto you that have been ordained unto this ministry, that inasmuch as you strip yourselves from jealousies and fears, and humble yourselves before me, for ye are not sufficiently humble, the veil shall be rent and you shall see me and know that I am—not with the carnal neither natural mind, but with the spiritual."  (Doctrine and Covenants 67:10)