Deuteronomy 31:8 The Lord himself goes before you and will be with you; he will never leave you nor forsake you. Do not be afraid; do not be discouraged.
When God spoke to Joshua it was to remind Him of the power and strength God would supply for all of Israel.
If we are willing to walk close to God, He is willing to watch over us every step of the way, keeping us strong and protected.
Trust in God and He will make sure you are safe from the evil of the world.