All right. But can you explain, step by step, HOW your Scripture quote (John 20:30-31) proves anything of the sort?
1- Jesus did alot of things not recorded.
2- Some of Jesus' acts and words were recorded in John.
3- The Holy Spirit testifies through John to the sufficiency of his account to lead man to Christ and to have eternal life as a result.
4- It follows that anyone who puts forth requirements for attaining eternal life that are absent from the Gospel of John is preaching another Gospel and is cursed.