John 11:21-27
Lord, Martha said to Jesus, if you had been here, my brother would not have died. But I know that even now God will give you whatever you ask. Jesus said to her, Your brother will rise again. Martha answered, I know he will rise again in the resurrection at the last day. Jesus said to her, I am the resurrection and the life. The one who believes in me will live, even though they die; and whoever lives by believing in me will never die. Do you believe this? Yes, Lord, she replied, I believe that you are the Messiah, the Son of God, who is to come into the world.
Jesus', 'Do you believe this,' entailed more than just a vague 'believing in Him', but specifically believing that Lazarus would rise again. We know this because Jesus later rebukes Martha for her lack of faith, referring back to when they spoke before:
John 11:38-40
Jesus, once more deeply moved, came to the tomb. It was a cave with a stone laid across the entrance. Take away the stone, he said. But, Lord, said Martha, the sister of the dead man, by this time there is a bad odour, for he has been there four days. Then Jesus said, Did I not tell you that if you believe, you will see the glory of God?
By extension, we are to believe in all aspects of Jesus' life in order that we may say we believe in Him. Believing that God raised Jesus from the dead necessarily entails believing that such an event had a relevance for oneself - after all, we are not to believe that Jesus rose from the dead for someone other than ourselves, are we?