Some memory verses.

for all have sinned and fall short of the glory of God, and are justified freely by his grace through the redemption that came by Christ Jesus. (Romans 3:23-24)

For it is by grace you have been saved, through faith-and this not from yourselves, it is the gift of God- not by works, so that no-one can boast. (Eph 2:8-9)

Like newborn babies, crave pure spiritual milk, so that by it you may grow up in your salvation, now that you have tasted that the Lord is good. (1 Pe 2:2)

Blessed are those who hunger and thirst for righteousness, for they will be filled. (Mt 5:6)

It is written: 'Man does not live by bread alone, but by every word that comes from the mouth of God' (Mt 4:4)

O God, you are my God, earnestly I seek you; my soul thirsts for you, my body longs for you, in a dry and weary land where there is no water. I have seen you in the sanctuary and beheld your power and your glory. Because your love is better than life, my lips will glorify you. I will praise you as long as I live, and in your name I will lift up my hands. My soul will be satisfied as with the richest of foods; with singing lips my mouth will praise you. On my bed I remember you; I think of you through the watches of the night. Because you are my help, I sing in the shadow of your wings. My soul clings to you; your right hand upholds me. (Psalm 63: 1-8)

His divine power has given us everything we need for life and godliness through our knowledge of him who called us by his own glory and goodness. Through these he has given us his very great and precious promises, so that through them you may participate in the divine nature and escape the corruption in the world caused by evil desires. For this very reason, make every effort to add to your faith goodness; and to goodness, knowledge; and to knowledge, self-control; and to self-control, perseverance; and to perseverance, godliness; and to godliness, brotherly kindness; and to brotherly kindness, love. For if you possess these qualities in increasing measure, they will keep you from being ineffective and unproductive in your knowledge of our Lord Jesus Christ. But if anyone does not have them, he is short-sighted and blind, and has forgotten that he has been cleansed from his past sins. Therefore, my brothers, be all the more eager to make your calling and election sure. For if you do these things, you will never fall, and you will receive a rich welcome into the eternal kingdom of our Lord and Saviour Jesus Christ. (2 Peter 1:3-11)

How can a young man keep his way pure? By living according to your Word. I seek you with all my heart; do not let me stray from your commands. I have hidden your word in my heart that I might not sin against you. (Psalm 119:9-11)