Moses encouraged the Israelites not to falter on the edge of the Promised Land, as the previous generation had done. He told them to "be strong and courageous," and he comforted them by telling them that God would not fail or forsake them.
Jewish tradition teaches that a person's income for the year is predetermined at Rosh Hashanah. The writer to the book of Hebrews quotes Deuteronomy 31:6 to encourage His readers to rely on God to provide for all their needs. He tells them to avoid greed and avarice because God has already promised not to forsake us:
"Make sure that your character is free from the love of money, being content with what you have; for He Himself has said [in Deuteronomy 31:6], 'I will never desert you, nor will I ever forsake you,' so that we confidently say [what is written in Psalm 118:6], 'The LORD is my helper, I will not be afraid. What will man do to me?'" (Hebrews 13:5-6)
"Be strong and courageous. ... He will not fail you or forsake you" (Deuteronomy 31:6). The High Holidays of Rosh Hashanah and Yom Kippur are primarily about our relationship with God as individuals and as a common people. These are appointed times for reconciling with one another and with our Father in Heaven. If we take the opportunity to turn to God in sincere repentance in the name of His Son, He will receive us.
People who have been abandoned or abused by a parent or spouse sometimes suffer with anxiety about their relationship with God. They might project their hurts and fears from human relationships onto their relationship with God. They fear that He will withdraw His love from them. Such a view of God makes a true faith relationship almost impossible. God wants His people to know that He will not fail us, nor will He abandon us.
Even in times when God punished Israel for disobedience, it was not as if He had abandoned them or cast them off. He punishes Israel as a father disciplines a beloved son. God is faithful to His people. Even when He sent the children of Israel into exile, He did not send them out alone. The rabbis teach that God's Dwelling Presence went with the people of Israel when they were driven from their land, and that He will return with them when they are gathered back into the land.
We can trust our Father in Heaven. He travels with us even in the lonely places of pain and exile. He will not fail us or forsake us.