As for Abraham going to war to save Lot, we have to understand that this was the Old Covenant and not the New Covenant. The Old has vanished away and the New Testament officially began (With no more Old Testament) when Jesus died upon the cross. For the Temple veil has been torn.
Sorry, Abraham's walk of faith was not of the Mosaic Law but should also be our walk of faith as well.
He rescued his nephew and was not rebuked for it.
And if you are of Christ, then you are a seed of Abraham, even heirs according to promise.
(Gal 3:29)
and a father of circumcision to those not of circumcision only, but also to those walking in the steps of the faith of our father Abraham during uncircumcision. For the promise was not through Law to Abraham, or to his seed, for him to be the heir of the world, but through a righteousness of faith.
(Rom 4:12-13)
So that those of faith are blessed with the faithful Abraham.
(Gal 3:9)
That the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive the promise of the Spirit through faith.
(Gal 3:14)