Romans 10:2 - Matthew Poole's English Annotations on the Holy Bible

For I bear them record, i.e. I must testify this of them, or of many of them, that they have a zeal of God; that they have a fervent desire to maintain the law of God, with all the Mosaical rites and ceremonies, as thinking thereby to promote the glory of God. But not according to knowledge; i.e. true and right knowledge. Though it be a warm, yet it is a blind zeal. They know not the will of God, or what that righteousness is which he will accept. They know not for what end the law and worship of God, under the Old Testament, was instituted. They knew not that Christ, in, and by whom, that law is fulfilled.