Jesus proclaimed that Lazarus will rise again. Martha thinks Jesus is referring to the resurrection at the last day, but Jesus had another view of resurrection.
Jesus proclaimed that HE is the resurrection and the life (11:25). Whenever someone believes in Jesus, although said person would die, that person would live. And that person would also never die to the age (11:26-27). Jesus's comment on being the resurrection is likely a reference to how after Jesus died, he rose from the dead three days later. He also provides life (including to someone who is close to Martha).
In response to Jesus's comments, Martha proclaimed that she believed that Jesus is the Christ and Son of God who came into the world (11:27). A "Christ" (also known as "Messiah") is also known as a Savior. It likely references how Jesus saves us, and if we're honest, we have done some screw-ups that require us to be saved from our own undoing.
Before Martha made that comment, Jesus asks Martha if she believes this. Believing in Jesus is essentially accepting that we need Lord Jesus (who is Son) as the resurrection and life and counting on Jesus and his resurrection for being the Savior. That's it for us. Jesus as Lord (and Son) has resurrection power and Jesus as Savior saves us from the final penalty that came from our screw-ups. When we believe in Jesus, we are guaranteed everlasting life that would ultimately not end.
For the readers who decided to accept Jesus and count on Him for saving us, you are guaranteed eternal life. I don't have a "I raise my hand" button or "I accepted Jesus" button because faith starts internally. (You can raise your hand though.)