Ye have said, It is vain to serve God: and what profit is it that we have kept his ordinance, and that we have walked mournfully before the LORD of hosts? Ye have said, It is vain to serve God - They strove to destroy the Divine worship; they asserted that it was vanity; that, if they performed acts of worship, they should be nothing the better; and if they abstained, they should be nothing the worse. This was their teaching to the people.
Walked mournfully - Even repentance they have declared to be useless. This was a high pitch of ungodliness; but see what follows; behold the general conclusions of these reprobates: -