The following exerpt is from the Prophets of God Sunday School Lesson listed on official LDS site.  
 
View the entire lesson from LDS.org.
 
  We Should Sustain the Lord’s Prophet  
 
  • Many people find it easy to believe in the prophets of the past. But it is much greater to believe in and follow the living prophet. We raise our hands to sustain the President of the Church as prophet, seer, and revelator.
  • How can we sustain the prophet? We should pray for him. His burdens are heavy, and he needs to be strengthened by the prayers of the Saints.
  • We should study his words. We can listen to his conference addresses or read them in Church publications.
  • We should follow his inspired teachings completely. We should not choose to follow part of his inspired counsel and discard that which is unpleasant or difficult. The Lord commanded us to follow the inspired teachings of his prophet:
  • “Thou shalt give heed unto all his [the prophet’s] words and commandments which he shall give unto you as he receiveth them, walking in all holiness before me; For his word ye shall receive, as if from mine own mouth, in all patience and faith” (D&C 21:4–5).
  • The Lord will never allow the President of the Church to lead us astray.