In order to obtain the eternal bread, the people have just asked Jesus what specific works they must perform. In other words, they rely on rituals, sacraments, and other good works to attain salvation. In response to this question, Jesus states that salvation does not depend on any particular good deed. Rather, salvation is dependent on belief in the One whom God has sent.
Every time we hear the word 'work,' it brings to mind some activity that we are required to perform. Certainly, as good Christians, we desire to be of service to the Lord, and indeed, we are expected to do so. In spite of this, Jesus presents a very different perspective on work - faith in Him. With our faith and the power of the Holy Spirit, we have the life of Christ within us and the good works that God has prepared for us to accomplish.
To accomplish the works of God within us, we must put our trust in Him as believers. The person whom God has sent for salvation is only one aspect of believing in Him; we must also believe in the person whom God has sent to prepare His good works in us every day.

Dear Heavenly Father, trusting You as my Savior is the most important thing to me. It is my belief that Jesus came to earth, died, and was raised from the dead for us. Please help me spread that message of hope and help to those around me. Allow me to continue trusting You with every step that I take. My belief in "Him Who the Father sent" is the only thing that will enable me to accomplish the works that God has prepared for me. 
In Jesus's name I pray. Amen.