Answer: The preface of the Lord’s Prayer (contained in these words, Our Father which art in heaven₁), teaches us, when we pray, to draw near to God with confidence of his fatherly goodness, and our interest therein₂; with reverence, and all other childlike dispositions₃, heavenly affections₄, and due apprehensions of his sovereign power, majesty, and gracious condescension₅: as also, to pray with and for others₆.

1. Matt 6:9
2. Luke 11:13; Romans 8:15
3. Isa 64:9
4. Psalm 123:1; Lam 3:41
5. Isa 63:15-16; Neh 1:4-6
6. Acts 12:5

For further study see:

1. WSC 100: What doth the preface of the Lord’s prayer teach us?