nov'-is (neophutos, "newly planted"): In this sense it is found in Septuagint of Job 14:9 and Isa 5:7. In the New Testament it occurs once only (1Ti 3:6), where it means a person newly planted in the Christian faith, a neophyte, a new convert, one who has recently become a Christian. This term occurs in the list which Paul gives of the qualifications which a Christian bishop must possess. The apostle instructs Timothy, that if any man desires the office of a bishop, he must not be "novice," must not be newly converted, or recently brought to the faith of Christ "lest he be lifted up with pride, and fall into the condemnation of the devil."
⇒See the definition of novice in the KJV Dictionary
This means that a recent convert runs the very serious risk of being wise in his own eyes, of despising those who are still on the level from which, by his conversion, he has been lifted; and so he becomes puffed up with high ideas of his own importance. He has not yet had time to discover his limitations, he is newly planted, he does not fully understand his true position in the Christian community, he overestimates himself. For these reasons he is peculiarly liable to instability, and to the other weaknesses and sins connected with an inflated opinion of his own powers. His pride is a sure indication of a coming fall. A novice, therefore, must on no account be appointed to the office in question, for he would be sure to bring disgrace upon it.
John Rutherfurd