1 Timothy 3:8-10

Also, let these be tested as to fitness first, then let them serve as ministers, as they are free from accusation.

Furthermore, men recommended as ministerial servants should have been “tested as to fitness,” giving evidence of having a sense of responsibility. That is not to say that they serve a probational term. Rather, they must have shown Christian maturity over a reasonable period of time (having been baptized at least one year), being men who are willing and able to attend to matters assigned to them. If a “serious” young man demonstrates these qualities, and he is humble and meets the other qualifications, the elders might recommend him for appointment even if he is not yet 20 years old. Other men may be much older when they show clearly that they meet the qualifications for ‘ministering in a fine manner, acquiring for themselves a fine standing and great freeness of speech.’