The covenant with Abraham was not something Abraham invented. A covenant with God is simply given by God on God's terms. That is true also of the covenant which we have in Jesus. God did not consult humankind before sending Jesus into the world. A covenant is a spontaneous act of divine love, an undeserved outreach and lifting up into a new relationship with God. A covenant is not basically a set of rules. It is freeing and elevating.
Our individual callings as disciples are personal covenants within the great covenant of Christianity. Taken by themselves they are not as grand as the great covenant. However, their nature is the same. They are an outreach to us and a lifting up. When we see our callings as covenants that are free and elevating, it is much easier to be faithful to them. Moreover, we will live our covenants with gratitude and joy.
As you called Abraham to give himself over to your guidance so you have called me, Lord. I do not know how long my journey will be but I believe that by its end you will have set me free and raised me to yourself.