In the first reading (Jer 17:5-8) we have a very straightforward message which applies to our time as much as to Jeremiah’s. This passage is in the form of a typical wise message which is also found in some psalms (including the responsorial psalm for today). We must remember that the way the writings attributed to Jeremiah came together was not that he wrote them, but that some of the remembered preachings of his were later recorded and only eventually added to and structured as we have them today. There is an early Greek verion of the OT called the Septuagint which in places has slightly different texts. Indeed the main force of our reading is also found in the ancient writings recorded of the Egyptian wise man, Amenemope (see here).
The second readig is from 1 Cor 15:12 onwards omitting verses 13-15. There was no real certainty throughout the OT that there was any life after death (perhaps this is why some saintly charaters were attributed very long lives). And it seems from our reading that even some Christians were a little uncertain about this, despite stories of Jesus appearing to people after His death. It is for this reason that Paul has this clear message in his letter here. It would have also been a comfort in the early church where Christians in some contexts were being put to death for their beliefs. It is now a comfort to usthat just as with Jesus, so also when someone dies, therie lif is not some much ended as brought to completion – fulfilled,
The gospel is from Luke 6:20-26 preseded by verses 17,18a (“He went down with them and stood on a level place. A large crowd of his disciples was there and a great number of people from all over Judea, from Jerusalem, and from the coastal region around Tyre and Sidon, 18 who had come to hear him and to be healed of their diseases“). This introduces what we now call the beatitudes – each starting with the word “happy,” followed by what we might call “woes” now translated as “alas for you who…” This is an uplifting message for those who need cheering up or just re-assuring. but also a warning for those who see themselves as well-off in worldly things.