Sandal Strap

Who is the coming “One mightier than” (Luke 3:16) John the Baptist?
“The Christ” (Luke 3:15).

What does John the Baptist mean by not being “worthy to loose” His “sandal strap” (Luke 3:16)?
In those days, the roads were nothing more than dirt paths littered with animal excrement, and foot coverings were crude sandals. Given how dirty people’s feet became from walking through the dust and excrement, the job of washing someone else’s feet was considered so low that only the lowest slaves were obliged to perform it. John the Baptist is saying that compared to Jesus, he is so worthless that he isn’t even worthy to be Jesus’ foot washing slave.

How does John's water baptism differ from Jesus' baptism?
John baptized “in water” but Jesus will baptize “in the Holy Spirit and fire” (Luke 3:16).

How else are they different?
John's baptism was symbolic, but Jesus' baptism is transformative. John's baptism symbolized a sinner's decision to repent from sins. But when Jesus baptizes - literally immerses - a sinner in the Holy Spirit, the Holy Spirit takes up residence in and fundamentally transforms the sinner from within so that the sins he used to enjoy become not sins that he still wants to enjoy but cannot, but rather sins that he now abhors and no longer desires. The transformation will be as radical as the effect that “fire” (Luke 3:16) has on anything placed in it.

If you claim to be born again, what are your feelings and desires today about the sins you used to enjoy?