Perhaps the fella was trying to say that when one is in Christ, he does fullfill the law perfectly, but only because he is in Christ.
The born-again Christian has no life apart from Jesus Christ; there is no half-n-half keeping the Law in our dead flesh and walking alive sometimes in the Spirit that seals us in Christ and into everything He is.
Lord Jesus Christ is our Savior, and not partially we ourselves a little bit also. Thus, the born-of-the-Spirit Christians can count on experiencing all the promises of God that pertain to His Son.
Perhaps this was what the preacher was trying to say?
Perhaps. If that is the case it was very sloppy. He wrote this “sermon” in 10 minutes. I guess it shows.