Encouragement to pray

And if you meet with troubles
And trials on the way,
Then cast your care on Jesus,
And don’t forget to pray.*

God the Father. Matthew 6:9; John 1:12; Jeremiah 33:3
Who He is. He is not only the Creator and Ruler of the universe, He is our Father. He is not a distant deity. We are in a relationship with Him.
What He does. He invites us to pray and promises to answer.

God the Son. Hebrews 4:14-16; Romans 8:34
Who He is. He is the Son of God, and He is our great High Priest. He is a priest made like unto sinful man, but has no sin. He knows and He feels our infirmities.
What He does. He intercedes for us. His standing as a substitutionary offering and a compassionate High Priest motivates us to come boldly to the throne of grace.

God the Spirit. John 14:26; Romans 8:26
Who He is. He is our Comforter, our Teacher, our Guide. 
What He does. He teaches us to pray, and intercedes for us when we know not how to pray as we ought.

Jesu, my Savior, Brother, Friend,
On Whom I cast my every care,
On Whom for all things I depend,
Inspire, and then accept, my prayer.**

Ephesians 3:20 Now unto him that is able to do exceeding abundantly above all that we ask or think, according to the power that worketh in us

* Excerpt from John Leland, 1793, in "Heavenly Armour," No. 129 in The Sacred Harp, 1844
** Excerpt from a 7-stanza hymn by Charles Wesley (1707-1788) in Hymns and Sacred Poems, 1742