To remember the word of God or God promises is very important. Because when we say God promises out loud our faith automatically will arise too. These are few of my favorite verses. When I'm in tough situation I usually says to my self these verses. It usually give me confidence to know that God is there ready to help me.

*I can do all things through Christ who strengthens me.....Philippians 4:13

*Yet in all these things we are more than conquerors through HIm loved us.....Romans 8:37

*But those who wait on the Lord shall renew their strength, They shall mount up with wings like eagles, They shall run and not be weary, They shall walk and not faint. .....Isaiah 40:31

that's why there is a different between believers and non believers.  non believers just depends on their side. Believers believe that God on their side