In order to hold your belief in this covenant topic you must believe that God contradicts himself rather than progressively reveals himself with the fullest representation of himself. The Lord Jesus Christ.
If you assume there are not two different designs for each covenant than you are right. However, they are placed in CONTRAST with each other throughout the New Testament. For example:
Jn. 1:17 For the law was given by Moses,
but grace and truth came by Jesus Christ.
However, if the Law covenant was given for a different design than the grace covenant and God's purpose was accomplished in both then there is no contradiction.
The law was not given to obtain eternal life (Gal. 3:21) but was given to reveal the knowledge of sin (Rom. 3:21). It was not given for justification (Rom. 3:19-20; Gal. 3:10-12) but given to lead people to faith in Christ (Gal. 3:24). The law was not designed for the justification of sinners but the covenant of grace was designed for the justification of "the ungodly" (Rom. 4:5).
And thus it is that Abraham was saved by Faith rather than law so one covenant flows into the other.
Paul argues the very opposite in Romans 4:13-16.
You cannot say the old covenant was not fulfilled it was by Jesus Christ who fulfilled it.
I never said that Jesus Christ did not fulfill the law covenant. Here is the crux of the issue! Why did he fulfill it? He was sinless before he ever left heaven. He was sinless in the body he took upon, as he knew no sin, did no sin and neither was sin found in him. Hence, he needed no justification before God
before or
after the incarnation.
Why did he fulfill it? Because all mankind were CONDEMNED by the law (Rom. 3:19-20) whether Jew or Gentile because the same standard of righteousness written on stones and skins is written on the conscience and man has violated that standard - sinned and the wages of sin is death.
Christ came under the law of God to satisfy its righteous demands by his OWN PERSONAL life and by his OWN DEATH as a SUBSTITUTE for the people the Father gave him in covenant agreement to give eternal life (Jn. 17:2).
It was always by faith by which we are now bound in the New covenant.
The New Covenant salvation was always present (Jn. 1:29) and NEVER by law covenant as that was not God's design for the law covenant. The law covenant in its greatest manifestation was "ADDED" to show the sinfulness of sin but "the law is NOT OF FAITH" - Gal. 3:12.
Christianity is a communal faith as well as individual. It is the dispensational method which dichotomize the Old From the New.
"Christianity" is a communal expression (Acts 2:41-47) but it is not a communal "faith" but it is an INDIVDIUAL faith (Jn. 1:13) not related to any covenant community. The "least to the greatest" in the New Covenant community do not have to be taught by men to know God (catechism) or have proxy faith because they ALL know God personally and individually separate from each other and from all others:
Jer. 31:34
And they shall teach no more every man his neighbour, and every man his brother, saying,
Know the LORD: for they shall
all know me,
from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more.
Infants must be taught to know God and infants in your concept of covenant community are "the least" are they not? Infants that die and go to heaven are taught by God not by men. However, infants that live in your covenant community must be taught by men. Jeremiah is talking about the new covenant and the covenant people have not been taught by men to "know God" (Jn. 17:3).