Like Jesus, the rabbis made frequent reference to “the Kingdom of Heaven.” A familiarity with the way “Kingdom of Heaven” is used in rabbinic literature is essential for understanding its use in the Gospels.
The Lord’s Prayer 4: “Thy Kingdom Come” (Part 1)

Probably no other aspect of Jesus’ teaching has been so greatly misunderstood as the Kingdom of Heaven. Certainly, few themes are more essential for understanding Jesus.
The Lord’s Prayer 1: Introduction

Too often, the importance of the Jewish background of the prayer and of the language that Jesus used has been overlooked or minimized.
The Lord’s Prayer 2: “Our Father Who Art in Heaven”

The description of God as “father” is not coincidental. The father figure was of great significance in the Hebrew family.