"For this reason I left you in Crete, that you should set in order the things that are lacking and appoint elders in every city as I commanded you,” Paul wrote to Titus (1'5).
This command shows that the ministry of Elders is indispensable to the building of the Lord's Ekklesia.
The Cretan situation apparently came about after Paul had ministered throughout the island and had not been able to complete the work. However, he was confident that Titus could do it.
He knew him well. He called him "a true son in our common faith" and "my partner and fellow worker" (Corinthians 8'23).
But above all he knew Titus had a heart for the Lord's People. Paul showed that he was thankful about this when he said to the Corinthians, "... thanks be to God who puts the same earnest care for you into the heart of Titus" (2 Corinthians 8'16).
Just the kind of man to appoint elders.