Deuteronomy 30:20

By loving the Lord your God, by obeying His voice, and by holding closely to Him; for He is your life (your good life, your abundant life, your fulfillment) and the length of your days, that you may live in the land which the Lord promised (swore) to give to your fathers, to Abraham, Isaac and Jacob.   

God is faithful to His promises. We strengthen our faith and relationship with God when we listen and obey the word. We know the voice of the good shepherd and respond to His guidance. We are allowing God to replace lack with abundance and sadness with joy.