And if the greatest of commands cannot be fulfilled by demand, we may expect the same to be true of lesser commands. Love must be instilled. It comes in response to love rather than lawful demands. But God shows His love for us in that while we were yet sinners Christ died for us. No one will be scared into heaven.
Love is the great commandment because it is the only effective motivation for our discipleship.
Love fulfills the intent of all other laws. God has always given directives to guide our spiritual relationship with him and our moral relationship with our fellowman. We would not know how to relate to God or how to serve Him if it were not revealed. God's directions tell us how to serve Him but do not define the extent of service. Our worship and service are expressions of love.