The blessing right before the Sh’ma centers on G-d’s revelation of Torah. An interesting fact, though, is that the evening blessing and the morning blessing are substantially different.
This matter is discussed in the Talmud (Berachot 12a) where the great authority Rav states, “If one omits to say ‘True and firm (emet v’yatziv)’ in the morning and ‘True and trustworthy’ (emet v’emunah) in the evening, he has not fulfilled his obligation, for it is said, “to declare Your lovingkindness in the morning and Your faithfulness at night.’” Here, Rav is focusing on the blessings immediately following the Sh’ma, but the same principle holds. The morning blessing emphasizes the things G-d has already done for us (like parting the Red Sea, and the whole Exodus story). The evening blessing, by contrast, is about faith in the future.
In similar fashion, the morning blessing Ahava rabbah,”with great love you have loved us” centers on the past. Ahavat olam, “Everlasting love,” on the other hand, is future oriented, with an emphasis on faith, our faith in G-d’s constant care for us. G-d’s love is indeed everlasting.
So, the morning blessing is all about G-d’s love in the past. The evening blessing is all about G-d’s love in the future. But what about the present? The love in the present is not from G-d to us, but from us to G-d. It is expressed in the first paragraph of the Sh’ma, “You shall love the Lord with all your heart.” The message is an important one: G-d did for us in the past, G-d will do for us in the future. But when will we ever give back to G-d?
The answer is: Now.