In all places of the earth, and among all people, there have been those who disclaim belief in the supernatural without having a perfect knowledge of it. They clamor that a sign be given them that they may know for certain that God lives, and that He is all-powerful both in Heaven and upon Earth. In Nephite annals many unbelievers came unto the people who denied this great truth, and also that "Christ shall come." Sherem, in the days of Jacob, the Prophet Nephi's brother, was the first who is recorded in the Book of Mormon as asking for such a sign. (Alma 1:1-15) Korihor who followed Nehor in the attempt to destroy the children of men, also asked for a sign. That sign was given to him.
And now Korihor said unto Alma: If thou wilt show me a sign, that I may be convinced that there is a God, yea, show unto me that He hath power, and then will I be convinced of the truth of thy words.
But Alma said unto him: Thou hast had signs enough; will ye tempt your God? Will ye say, Show unto me a sign, when ye have the testimony of all these my brethren, and also all the holy prophets? The Scriptures are laid before thee, yea, and all things denote there is a God; yea, even the Earth, and all things that are upon the face of it, yea, and its motion, yea, and also all the planets which move in their regular form do witness that there is a Supreme Creator.
And yet do ye go about, leading away the hearts of this people, testifying unto them there is no God? And yet will ye deny against all these witnesses? And he said: Yea, I will deny, except ye shall show me a sign. (Alma 30:43-45)
We will quote from Elder John Morgan who has assembled some pertinent scripture under the heading Faith and Signs. We often hear the same cry that greeted the ears of Jesus, "Master, we would see a sign from Thee. But He answered and said unto them, an evil and adulterous generation seeketh after a sign." (Rom. 10:17)
After the death and resurrection of Jesus, He left this grand test of faith upon record, to serve as a guide for all future generations: "And these signs shall follow them that believe (that is, have faith); In My Name shall they cast out devils; they shall speak with new tongues; they shall take up serpents; and if they drink any deadly thing, it shall not hurt them; they shall lay hands on the sick, and they shall recover." (Mark 16:17-18) (John Morgan, Plan of Salvation, p. 12)