Here we have the clue as to how Jesus could perform the miracles and signs He did whilst having emptied Himself of His divine privileges- Philippians 2 v 6-8. John the Baptist is quoted as stating: 'God gives Him the Spirit without limit'. A fully human Son of God gave His life to obedience to His Father and when the Spirit moved was able to do great miracles in reliance on the Holy Spirit (Luke 5 v 17).
John the Baptist's testimony about Jesus has special import as he had led the way and was not viewing Jesus as a rival, but understood that he himself would fade as Jesus' light grew stronger. John the apostle places the Baptist John very highly in the ranks of humans, but ensures that he doesn't supplant Jesus. His own disciples did not like to see him in second place and it would have been easy for him to allow their complaints to make him feel injured and unjustifiably forgotten. Showing sympathy for others can be a two-edged sword as those who feel hard done by sense that they now have support for their cause. We will read of times when Jesus seemingly treated people harshly, but He could see ahead and always be aware of what was the greater good. John the Baptist regarded himself as the friend of the bridegroom-the best man-and his job was to make sure that the coming together of bride and groom happened without hitch or interference. Christ the bridegroom had arrived and had met His bride, the people of Israel (Isaiah 54 v 5), and so his job was complete!