The word used here for ‘tremble’ can also be translated dread, fear, or even be terrified. Following the will of God can seem terrifying and scary, but verse 9 gives us one of the greatest assurances in all of Scripture; ‘surely the Lord your God is with you wherever you go.’ Whatever situation you face, whatever He is calling you to, whatever trial you are going through, God is with you. He is with you in everything, and will not leave you to walk alone.