Believe
Believing in Christ means trusting in God so strongly that you are willing to commit your life to Him. It also means trusting Him personally as your Lord and Savior, and coming to know Him personally.
Belong
Belonging to Christ means being at the disposal of Christ in life and death, and being influenced by the Holy Spirit. It also means belonging to God's family, the church, and other people.
Become
Becoming like Christ does not mean losing your personality or becoming a mindless clone. God created your uniqueness, so He certainly doesn't want to destroy it. Christlikeness is all about transforming your character, not your personality.