Maybe we're just defining our terms differently. When I think of "rules," I think "commandments." The following verses, among others, are all taken from the New Testament as opposed to the Old Testament:
Matthew 19:17 And he said unto him, Why callest thou me good? there is none good but one, that is, God: but if thou wilt enter into life, keep the commandments.
John 14:15 If ye love me, keep my commandments.
John 14:21 He that hath my commandments, and keepeth them, he it is that loveth me: and he that loveth me shall be loved of my Father, and I will love him, and will manifest myself to him.
John 15:10 If ye keep my commandments, ye shall abide in my love; even as I have kept my Father's commandments, and abide in his love.
1 Corinthians 7:19 Circumcision is nothing, and uncircumcision is nothing, but the keeping of the commandments of God.
1 John 2:3-4 And hereby we do know that we know him, if we keep his commandments. He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.
1 John 3:22,24 And whatsoever we ask, we receive of him, because we keep his commandments, and do those things that are pleasing in his sight. And he that keepeth his commandments dwelleth in him, and he in him. And hereby we know that he abideth in us, by the Spirit which he hath given us.
John 5:2-3 By this we know that we love the children of God, when we love God, and keep his commandments. For this is the love of God, that we keep his commandments: and his commandments are not grievous.
I'm not trying to minimize the importance of the two greatest commandments (loving God and loving our fellow man), but there are commandments other than these, and we as Christians are expected to keep them -- all of them. So, either you disagree, and simply gloss over such verses, or you agree but don't consider commandments to be rules. I'm curious... Which is it?
By the way, I also consider sacraments and ordinances to have been initiated by Jesus Christ. Consequently, I consider receiving them to be part of what is meant by keeping His commandments.