Charity, this post is both right and wrong. Like Abraham, we Gentiles in Christ are expected to walk in God's Earth just as Abraham and his descendants were required to walk the length and breadth within God's "Earth" here on our "planet." The source text of Genesis 13:14-17 needs to be unpacked and understood a little differently from how the scholars have translated these verses for us to read.
Titus 1:2 which you referenced said the following: -
Titus 1:1-3: - 1:1 Paul, a bondservant of God and an apostle of Jesus Christ, according to the faith of God's elect and the acknowledgment of the truth which accords with godliness, 2 in hope of eternal life which God, who cannot lie, promised before time began, 3 but has in due time manifested His word through preaching, which was committed to me according to the commandment of God our Savior;
Echoes the same view of an ancient covenant/promise from God which Christ referenced in Matt 13:52, which points to an ancient salvation covenant from the beginning of time which has been refreshed through the actions of Christ for the salvation of all the people who have and will live on the face of this earth. This salvation covenant was offered to Cain, and it seems to me that Cain allowed the influence of Satan to lead him down a very different pathway away from God's love for mankind.
What has been labelled by man as the "Old" and the "New" covenant found in Exodus 19 and Jeremiah 31, is the Kingdom of Priests, a Holy Nation and God's Possession among the Nations covenant, which also has embedded within it the Salvation Covenant.
Sadly, I think that you are missing what Charity was posting and alluding to with respect to the ancient covenant was.
You have pointed to a "Covenant of redemption" for all of mankind, and Charity in referencing Titus 1:2 was also pointing to the same "Covenant of Salvation," another "title" for the same covenantal promises, of redemptions that you have pointed towards.
The theological understanding of how this is played out by God seems to me to be the sticking point in many discussions between people of faith with understanding, which is not necessarily from God.
God's intention at Mt Sinai, was for Abraham's blood descendants to become His Kingdom of Priests, His Holy Nation and His possession among the nations, i.e. the Gentiles, but was rejected and the nation of Israel rebelled against this covenant, labelled the "old covenant." Again it is God's stated intention that in our near future that He will make like new again this same Kingdom of Priests, a Holy Nation and His Possession among the Nations Covenant once more around 3,500 years after the initial entering into the first, i.e. the labelled "Old Covenant," and so that Abraham's blood descendants can be a blessing to all of the nations/peoples of the earth. As such Charity was correct in her statement,: -
"Believing Gentiles during the Acts were blessed with faithful Abraham, but by nature and in the flesh Gentiles were strangers from the covenant of promise: and in the teaching concerning the Church which is the Body of Christ no covenant of any description is known."
Now it is man in his befuddled understanding that has brought confusion into how God intends to work out mankind's' salvation and redemption in our future.
Shalom.