The answer
St. John the Baptist was in prison and he knew that his end was near. He knew exactly who our Lord Jesus Christ was. St. John noticed that although he was in prison, his disciples still loved him dearly, never left him, always attended on him, and were ready to receive instructions from him. At that point in his life, He wanted his disciples to turn their attention to the true Messiah; therefore, he sent them to our Lord Christ with this question,in order to have the affirmation from His blessed mouth. It was not out of doubt that he had sent them. It was for them to gain knowledge, and be confirmed in the faith.Answered by His Eminence Metropolitan Youssef (opens in a new tab)