"It is a great thing to inquire at the hands of God, or to come into His presence; and we feel fearful to approach Him on subjects that are of little or no consequence, to satisfy the queries of individuals, especially about things the knowledge of which men ought to obtain in all sincerity, before God, for themselves." (Joseph Smith, HC, v. 1, ch. 24)
Mary Lightner and Joseph describes angellic visitor when she prayed concerning Joseph's proposal of marriage
"I made it a subject of prayer and I worried about it because I did not dare to speak to a living being except Brigham Young. I went out and got between three haystacks where no one could see me. As I knelt down I thought, why not pray as Moses did? He prayed with his hands raised. When his hands were raised, Israel was victorious, but when they were not raised, the Philistines were victorious. I lifted my hands and I have heard Joseph say the angels covered their faces. I knelt down and if ever a poor mortal prayed, I did. A few nights after that an angel of the Lord came to me and if ever a thrill went through a mortal, it went through me. I gazed upon the clothes and figure but the eyes were like lightning. They pierced me from the crown of my head to the soles of my feet. I was frightened almost to death for a moment. I tried to waken my aunt, but I could not. The angel leaned over me and the light was very great, although it was night. When my aunt woke up she said she had seen a figure in white robes pass from our bed to my mother's bed and pass out of the window.
"Joseph came up the next Sabbath. He said, ‘Have you had a witness yet?’ ‘No.’ ‘Well,’ said he, ‘the angel expressly told me you should have.’ Said I, ‘I have not had a witness, but I have seen something I have never seen before. I saw an angel and I was frightened almost to death. I did not speak.’ He studied a while and put his elbows on his knees and his face in his hands. He looked up and said, ‘How could you have been such a coward?’ Said I, ‘I was weak.’ ‘Did you think to say, 'Father, help me?'‘ ‘No.’ ‘Well, if you had just said that, your mouth would have been opened for that was an angel of the living God. He came to you with more knowledge, intelligence, and light than I have ever dared to reveal.’ I said, ‘If that was an angel of light, why did he not speak to me?’ ‘You covered your face and for this reason the angel was insulted.’ Said I, ‘Will it ever come again?’ He thought a moment and then said, ‘No, not the same one, but if you are faithful you shall see greater things than that.’ And then he gave me three signs of what would take place in my own family, although my husband was far away from me at the time. Every work came true. I went forward and was sealed to him. Brigham Young performed the sealing, and Heber C. Kimball the blessing." (Mary Lightner, Address to Brigham Young University, 1905)