He must not be a new convert, lest, being elated by pride, he may fall under the sentence of the devil
Other versions
King James Version
Not a novice, lest being lifted up with pride he fall into the condemnation of the devil. English Standard Version
He must not be a recent convert, or he may become puffed up with conceit and fall into the condemnation of the devil.New International Version
He must not be a recent convert, or he may become conceited and fall under the same judgment as the devil.