“Unless the LORD builds the house, its builders labor in vain. Unless the LORD watches over the city, the watchmen stand guard in vain.” (Psalm 127:1)
We do not go to someone having no training and experience in construction to get a building project done. We hire trained professionals for it. When the time came for the making of the Tabernacle, God chose skilled workmen for the job. Similarly, He expects us to be skilled workmen in the ministry of the Word.
But, it is vain to rely just on knowledge, training, and experience. Unless the Lord builds, all labour is in vain.
Similarly, a man with a heart problem is expected to go to a cardiologist and not to a dentist. However, unless the Lord heals, the doctors labour but in vain.
Paul tells Timothy about the training of a soldier. An untrained soldier is not expected to be sent into battle. Similarly, an untrained athlete is unqualified for any competition. The Bible encourages wisdom, understanding, and skill, but it caps it with the instruction to not rely in our own understanding but trust the Lord with all our heart.