Luke 7:18-28 was set prior to John the Baptist's execution. Here we find John calling two of his disciples to go to Jesus and ask Him: "Art Thou that should come? Or we look for another?" In other words, their question was, "Are you truly the Messiah?" It's quite shocking to me to read this story because, first, John the Baptist (according to Sunday School stories and messages) was always portrayed as a courageous, determined messenger who was prophesied to prepare the way of the Lord. Second, I never heard about him doubting and desperately trying to seek assurance that Jesus is truly the Savior.
Since it was so unexpected, the thought of it struck me so hard. Isaiah 40:3 (KJV) proclaims: "The voice of him that crieth in the wilderness, Prepare ye the way of the Lord, make straight in the desert a highway for our God.". In relation to that, Malachi 3:1 (KJV) states that "Behold, I will send my
messenger, and he shall prepare the way before me: and the Lord, whom ye seek, shall suddenly come to his temple, even the messenger of the covenant, whom ye delight in: behold, he shall come, saith the Lord of hosts." He was a man who was DEEMED to specifically set the stage for Christ's ministry on earth. He was written about long before he was ever born to do such an important work. Considering all these special things about this man, we most probably (I'm sure you do) regard him as strong and unmovable in his faith and belief. That's the thing about reading about a "character" in the Bible I guess, we tend to attribute such great traits (sometimes they seem to not be real people) and forget that, in fact, they are just humans -- that were GREATLY used by God. Samson, for example, was a man of literal strength; Esther, a woman of true beauty; Mary, a willing damsel to be used as an instrument for God's greater plan... all of them, were just like you and me. People. They could feel pain and heartache. They could feel happiness. They get hungry. They get jealous, They get sleepy. They feel love. But most of all, people feel fear -- fear that "what if what we've believed in is not true?" That's why we have doubts... and John the Baptist had that tinge of doubt a short while before he was to die.