Hebrews 9:15-17 - The writer here is comparing old and new covenants - not the testaments. The translation in the King James Version obscures the meaning of this passage somewhat, but other translations make it clearer.

Testament:

Testator

Gift

Heirs

Conditions

Death of testator

Executor

Probated

When conditions met and the gift received, it is not reversible.

Covenant:

Covenant maker

Mediator

Death of sacrifice

Relationsip established

Must continue in the conditions of the covenant to maintain this relationship.

In this text:

There is a covenant maker.

There is a mediator.

There is a blood sacrifice.

There is a relationship established.

This relationship must be maintained to be blessed under the conditions of the covenant.