Some people leave a will naming those people who will receive the inheritance after their death. Of course, everyone wants to be named in that will but not all will be. In the same way, in heavenly matters there are things similar to earthly ones, for example, in this case God has appointed us in His testament leaving us an inheritance, and we give glory to God for this.
There is a passage in the Bible that tells us about this:
4 But when the set time had fully come, God sent his Son, born of a woman, born under the law,
5 to redeem those under the law, that we might receive adoption to sonship.
6 Because you are his sons, God sent the Spirit of his Son into our hearts, the Spirit who calls out, “Abba, Father.”
7 So you are no longer a slave, but God’s child; and since you are his child, God has made you also an heir.
Galatians 4: 4-7