I love our security in Christ, and how it is not based on me and my flimsy willpower or fluctuating strength. It is made and kept going, formed and sustained by the mighty will and power of God Himself! Thus, it is an unbreakable and perfect covenant! This covenant, the New Covenant, is eternal. It is held together by God and won't ever fail.
This covenant wasn't even made between me and God - it was made between God and Jesus, His Son! They made this agreement, and with two perfect, unchangeable, unfailing, totally trustworthy, completely able parties making this covenant, we can be sure it will never be broken, fade, change, or be revoked! It is sure and settled, as sure as any of God's Words, which are forever settled in heaven!
Because the covenant wasn't between us and God but between Jesus and the Father, we ourselves can't mess it up or break it! Once we have believed, we enter into the covenant as benefactors of all its blessings through Jesus and His priestly work on our behalf. We get all the benefits of the covenant without doing anything; we simply receive them by grace through faith. This blessing of receiving all the benefits (like the inheritance set up in a will) is the gift of God, based on His promises, not our promise to 'do' anything to earn or keep earning the benefits. And God's gifts are irrevocable: we experience the full benefits of this covenant irrevocably!
This covenant is based on perfect things. It is based on better and perfect promises, that God, who cannot lie and who is perfectly faithful, will be sure to keep for us. It is inaugurated by a better priest/mediator, Christ Himself. It is set up through a better, perfect sacrifice, the sacrificial death of Christ Himself, the perfect and spotless lamb slain from the foundation of the world! It is written in His own precious blood, the blood that speaks better than any sacrificial blood and which doesn't just cover our sin but actually takes away our sin! This blood sacrifice is so perfect and so sufficient that it needed to be offered only once, once for all it did the job of making us perfect before God forever!
This covenant is an eternal covenant that is in place forever! It lasts for as long as Christ's perfect sacrifice lasts - Forever! It lasts for as long as His intercession for us lasts - Forever! It lasts for as long as His perfect righteousness given to us lasts - Forever! It lasts for as long as God is faithful - Forever! It lasts for as long as God's Word endures - Forever! It lasts for as long as God Himself lasts - Forever!
That means we are secure forever in this perfect and beautiful NEW covenant!