Contemporary English Version (CEV)
Melchizedek kind of comes out of nowhere. He seems to play a small role in Genesis, and yet here in Hebrews he is referenced and given center stage. He plays a much larger role than he probably imagined.
The lesson here, in my opinion, is that you don't truly understand the impact of your actions. You may be able to grasp the short-term impact, but the long-term impact is far beyond our ability to grasp it. As a pastor I greatly respect once said, "You may be the answer to someone's prayer." The hard part is internalizing that you may not see the answer realized. You may not gain the satisfaction of seeing the full impact of your actions, but you impact people everyday, and that impact often lasts far longer than you might imagine.
So continue to serve and love and give freely. Trust that this will impact others more than you know, and that the Holy Spirit will use your life to glorify God.