The most challenging thing for Christiandom to realize is how to recognize the Holy Ghost's influence.
The Influence of the Holy Ghost
The Apostle Paul taught what the influence of the Holy Spirit feels like. "But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith. (Gal. 5:22)" Likewise did the Prophet Joseph Smith teach, "It will whisper peace and joy to their souls; it will take malice, hatred, strife and all evil from their hearts; and their whole desire will be to do good, bring forth righteousness and build up the kingdom of God. (Manuscript History of Brigham Young, p. 529)"
The Holy Ghost will bear witness of the truthfulness of the Book of Mormon and the Bible, because the Spirit of Truth cannot be restrained. Every time I read the Book of Mormon, the Spirit reconfirms the truth of that Book and the reality of Jesus Christ the Son of God. It also confirms the prophetic mantle that was on Joseph Smith and that is currently on Thomas S. Monson.
Now, dear reader, the Spirit speaks in different ways to different people, and one must find and learn to recognize the way it speaks to him. For me, it is a tangible feeling of warmth and joy unspeakable. This warm, joyous feeling lifts my mind to a higher plain. My thoughts are clear, my hear rejoices.
Modern prophets can help describe the Spirit's workings better than I. In the May 2000 issue of the Ensign, President Boyd K. Packer taught, "The voice of the Spirit is a still, small voice—a voice that is felt rather than heard. It is a spiritual voice that comes into the mind as a thought put into your heart." President Joseph Smith taught, "A person may profit by noticing the first intimation of the spirit of revelation; for instance, when you feel pure intelligence flowing into you, it may give you sudden strokes of ideas, so that by noticing it, you may find it fulfilled the same day or soon; (i.e.) those things that were presented unto your minds by the Spirit of God, will come to pass; and thus by learning the Spirit of God and understanding it, you may grow into the principle of revelation, until you become perfect in Christ Jesus. (History of the Church, 3:381)"
When the Holy Ghost speaks, sometimes words cannot describe its influence, although they are helpful. President James E. Faust said, "The Holy Ghost bears witness to us of the truth and impresses upon our souls the reality of God the Father and His Son, Jesus Christ, so surely that no earthly power or authority can separate us from that knowledge. (April 2001 General Conference, "Born Again"; see May 2001 Ensign)" When the Holy Ghost speaks, although one may not know how to explain it, one knows the Spirit is speaking.
I know that the Holy Ghost is real and does speak to man. I know that it will testify to the veracity of the Book of Mormon and to Joseph Smith's calling as a Prophet. If one works at it hard enough with a sincere heart, God will answer him through revelation from the Holy Ghost. In the name of Jesus the Messiah. Amen.