There are many who twist the meanings of the terms ordinance and sacrament. When I use the terms I differentiate between them as follows:
a) A sacrament is a work that contributes to or necessary for salvation. If an institution portrays a religious activity as a requirement for salvation, then it is a sacrament regardless of what they call it otherwise.
b) An ordinance is merely an outward expression of something that has already taken place internally and spiritually. The two ordinances identified in scripture include immersion (baptizo) and the “Lord’s supper”.
Jesus was immersed to fulfill all righteousness and believers throughout the gospels, the book of Acts and the first century church were immersed as an outward testimony of their belief. They weren’t saved by immersion, but immersion was an expression and testimony to others of their salvation.
The same with perceiving the body and blood of Messiah represented by the unleavened bread and wine used in the Passover Sedar meal. Jesus instructed “As often as you do this, this do in remembrance of me” and Paul goes on to say that we should not partake of it unless we understand this representation (1 Cor 11:23-27)