Know what 'things'?Jesus said this to his students after washing their feet. He did more than this, however. He also explained how becoming a servant of others was the key to pleasing God, and becoming one of God's humble loving servants.
Jesus communicated this both by his teaching as well as by showing them. This is why he began washing their feet.
Now Jesus is saying that if they understood this, they would be "blessed."
What does 'blessed' mean?"Blessed" in this verse is being translated from the Greek word μακάριος (makarios). This word means, "blessed," but also "happy" according to the lexicon, but also "well off" and "fortunate."
This communicates that coming to understand our position as servant is a blessing. It is something that ultimately comes from God. The Supreme Being will open the door for those who decide they want to enter. But the door being open is still a gift.
Jesus came - as sent by the Supreme Being - to offer us this gift. He came to show us that each of us can make the choice and decide to get closer to God.
Once we make that steadfast choice, God will open the door.
This is why he said:
"Not everyone who says to me, 'Lord, Lord,' will enter the kingdom of heaven, but only he who does the will of my Father who is in heaven." (Matt. 7:21)
What is doing the will of God?Doing someone else's "will" also requires we know what pleases them. This was a primary purpose for Jesus' teachings. He taught his students what pleases the Supreme Being.
Jesus taught that doing the will of God, first and foremost, means loving Him. God does not need anything from us. He can do anything He wants. He doesn't need us to be His servants.
God is pleased simply by us loving Him. The Supreme Being wants our love.
Loving someone else means abandoning our own interests and caring for that person. Jesus advised that we point our love towards God because this is what pleases God:
"'Love the Lord your God with all your heart and with all your soul and with all your mind.' This is the first and greatest commandment." (Matt. 22:37-38)