The five Books of Moses were the only ones that the Sadducees recognized in the canon of the Old Testament and there is no mention in them of the Resurrection; so they denied it. The Lord shows the reality of the Resurrection precisely by these five Books and says: “Have you not read what was said to you by God, ‘I am the God of Abraham, Isaac and Jacob?’” (cf. Mt 22:31-32). God therefore takes these three and in his very name they become the name of God. To understand who this God is it is necessary to see these figures who became the name of God, a name of God, who are immersed in God. In this way we see that anyone who is in the name of God, who is immersed in God, is alive, because God — the Lord says — is not a God of the dead but of the living, and if he is the God of the latter, he is a God of the living.
The living are alive because they are in our memory, in God’s life. And this happens to us in being baptized: we come to be inserted in the name of God, so that we belong to this name and his name becomes our name and we too, with our witness — like the three in the Old Testament — can be witnesses of God, a sign of who this God is, a name of this God.
Consequently, being baptized means being united to God; in a unique, new existence we belong to God, we are immersed in God himself.
[Pope Benedict, Lectio 11 June 2012]