A Covenant is an agreement between these two parties. By it one agrees to give to, or do for, the other something on certain conditions. But the fact that a Covenant exists between God and man, implies that at some time there had been disagreement. God and holy angels do not need to enter into Covenant. Next, the possibility of a Covenant.
All Covenants have Form.
The expressed or implied agreement is made visible, and impressed, and sanctioned, by an outward deed, signature, and seal. The outward form, the signature, the sealing of this Covenant, is the Sacrament of Baptism. The seal is not part of the Covenant. Under God's Ordinance the two are not to be separated. The Covenant may take place before, or after, or at the same time, as the declaration and sign of it.