Believe and understand what it really means that Jesus is the Messiah - that He existed before Abraham was born and is not only sent to judge but to save too. It is He who rids you of the sins that damn us so you need to hold to His teachings so you are His disciple so He will do this. You will need to believe that He did die on that cross but was raised to life again and lives forever having been dead and now alive and immortal. So He is alive to save His disciples by freeing us from our serious sins. So He was loving to God and obeyed God even dying to satisfy God's will and showed Himself worthy to be called a true Son to God - and God showed He accepted Jesus as a true Son by recognising this loving obedience and raising Him from the dead. These things you certainly need to believe to be a true Christian disciple.
