Your body needs air, water and food for survival, sustenance and strength.
Without them, you will
(1) suffocate without air in 3 minutes.
(2) shrivel without water in 3 days.
(3) starve to death without food in 3 weeks.
Likewise, your soul needs
(1) the breath of God – constant prayers in the Spirit (1 Thess 5:17; Eph 6:18; Jude 1:20),
(2) living waters – springing out from the indwelling Holy Spirit, John 4:14; 7:37-39)
(3) living words of Jesus – the Bread from Heaven, Bread of Life (Matt 4:4; John 6:32, 35, 48. 51)
So that you can
a) grow up to the measure of the stature of Christ
b) be strong in the faith
c) serve God with all patience and perseverance in all that you are and do.