When I was younger, I was confused by verses like the one above. While everyone else was being handed out parcels of land on which to build and farm, the Levites were "rewarded" by not getting land, but by serving the Lord as priests. Or in Rev. 7:14-15, "... These are the ones who come out of the great tribulation, and they have washed their robes and made them white in the blood of the Lamb. For this reason they are before the throne of God, and they serve Him day and night in His temple..." Being made a servant didn't sound like any kind of reward I would want.
But as I matured in my walk of faith and learned more and experienced more about all of God's beautiful attributes, I started to understand how wonderful such an honor would be. Imagine if there were a person who ended all the world's wars, who solved every nation's need for food and power, who cured all diseases, who made a way for us all to live in peace, with all our needs being met, and limitless opportunities ahead of us. This person is beautiful, talented, and popular. Then imagine one day they asked you to come work for them. You'd see this amazing person in the halls every day. They'd remember your name and ask about your family, and if you had any needs or concerns they would take personal care of it. You'd be the envy of everyone else in the world! If you can get even the slightest hint of how that might be a good situation, then you have only just tasted the first morsel of how glorious it would be to serve the Lord in His courts. This is how David was able to say, "For a day in Your courtyards is better than a thousand elsewhere..." (Ps 84:10)
The Levites didn't need farmland because God would provide for them, and those who serve in the temple of the Lord will also have all of their needs met. As the rest of Revelation 7 goes on to say: "... They will no longer hunger nor thirst, nor will the sun beat down on them, nor any scorching heat; for the Lamb in the center of the throne will be their shepherd, and will guide them to springs of the water of life; and God will wipe every tear from their eyes." What a life that will be!
If you find yourself struggling to see the reward of just being in God's glorious presence, it probably means you are inexperienced in seeing God's beauty, His majesty, and His glory, and the best way to improve your vision is to prayerfully (that's important!) dig into your Bible. Think about all the good things He has done for others and for you. Correct your faulty ideas about God being mean or angry with you, because anything that might have caused His anger has been nailed to the cross. Enjoy the sweet freedom of being a guiltless son or daughter, and look forward to the day when you will see Him face to face.