When the Second Coming happens, how will we know it really is the Savior?

Before the Second Coming of Jesus Christ, there will be many signs, though many people will not recognize those signs. The culminating event, however, will be unmistakable. For one thing, the Savior Himself told His disciples that when He comes again, it won’t be in some obscure or secret manner but rather “with power and great glory” (see Matthew 24:26–27, 30; see also Joseph Smith—Matthew 1:25–26, 36). At His Second Coming, Jesus Christ will descend out of the heavens (see Acts 1:9–11), and He will be seen by all people (see D&C 101:23). Until that time, the key for us is to strive to live worthily, look for the signs, and treasure up the word of Christ so that we will not be deceived by false Christs and false prophets (see Joseph Smith—Matthew 1:5–6, 21–22, 37).