Jesus was turning from the larger group that was sent out and looking back to the twelve, saying that they were blessed to see the beginnings, the visible spread of the kingdom of God.
Our role is not the same as theirs. But our eyes and ears are also blessed if we have been given a spiritual birth; if we are born again we too can see the kingdom of God in manifestation. It may not seem as spectacular to the natural eye or sound as wonderful to the natural ear. Yet every time someone is delivered from the kingdom of darkness into the kingdom of light, we are witnessing the spread of the King’s reign.
Elijah labored in prayer until he saw one tiny little cloud, and then he knew the downpour was coming (1 Kings 18:41-45). If you are moving with the Spirit of God, you can see the things others miss. But is for the benefit of others; your reward is to be able to see it at all.
Future grace is what motivated the prophets (1 Peter 1:10-12). The future was revealed to them, but these revelations were given not for themselves mainly, but for our good in these Gospel times. This didn’t make them discouraged and inactive; it empowered them to unselfishly testify in the Spirit for the partial good of their own generation, and for the full benefit of posterity.
We must encourage life and work in the church that is motivated by selfless love. Engaging in ministry out of a need to feel self-worth will bear little eternal fruit. It is not only about serving ourselves, or even serving others, but serving others in service to God. We are working for the future, and we are blessed to be seeing and hearing about some of the fruit of it right now.