Why does Christianity oppose what God commands Israel regarding the eterrnal covenant we have with our Creator? You already asked this and it was explained to you in great detail that your Christian dogma is impotent to negate God's clear word on the matter that the covenant of Israel as echoed by the prophets, is clearly about the focus of honoring God's gift of life and making the world one of justice, mercy and compassion for the lives to follow our own.
Christianity is more closely compared to the Egyptian obsession with death and the "afterlife" often to the detriment of their own lives and the lives of others they disregard in belief that only those who believe as they do deserve or merit God's blessing and all others are inferior, cursed and deserve eternal torture in a demon deity ruled underworld hell.
To your chagrin, the fact that God's covenant with Israel obligates us to use the gifts and blessings we have in this world to make it better for ourselves, for our families and for the rest of the world doesn’t change. Life is our greatest gift from God. We are also here to enjoy that and share that joy. There isn't a thing wrong with doing good to feel good or to try to help another feel better about themselves.
We are partners with God and our fellow living creatures working to repair and restore it to harmony and a state of perfection. This is called Tikkun Olam or Repair of the World. We aren't expected to BE perfect but to strive toward it and help along others on the way as well as be willing to take the hand of another when we need help. Teshuvah meaning repentance and return involves specific steps to being accountable when we make mistakes or do things to hurt another so that we learn from our mistakes and to help guide us back on the path of righteousness. In focusing on our deeds and how we live and treat one another, we come to greater awareness of the Divine , our direct connection to our Creator and the purpose for our existence.
The world to come..whatever it is..will take care of itself.
It's this world that we are entrusted with in the here and now.
Judaism teaches that humanity's role is to work with each other to help God with perfecting and restoring or repairing anything out of harmony, any and all injustice or opression, any poverty, sickness, etc. Our walk with Hashem is more about deed than creed.
It isn't about earning a ticket into heaven. It is about fulfilling what we believe our purpose for existence is all about and how we achieve understanding of our connection to one another and to our Creator.
For many people, it appears to be a slow process of growth into an awareness of our connection to God, rather than some kind of overwhelming divine revelatory moment.
This is a very different world view and path than the perspective from one who belongs to a faith that teaches them that " works" mean nothing.
They are indoctrinated to believe that humans are born in a sinful state that requires appeasement through a symbolic human sacrifice and the "blood" of the demigod to be justified to exist without eternal torture. Torah teaches that how we live and relate to all living shows what we honor and believe and that the purpose of our covenant is to be a light unto the nations as an example of how to connect to God and honor the gift of life from God.
The great sage Hillel, whom you may recognize as the one who declared not only that "What is distasteful to you do not do to another", also left us this quote that sums up the ethical lessons of Judaism
If I am not for myself, who will be for me?
If I am for myself alone, what am I?
If not now, when?
Life is our greatest gift from God. We are also here to enjoy that and share that joy.
It is the role of Israel to struggle with God and find our place in God's creation to make it a better one.
Torah stresses, justice, justice, shall you pursue.
I've learned that justice without mercy is seldom truly just.
Mercy without justice is often unmerciful to those who have been victimized by injustice.
The path of Klal Yisrael is a struggle to find our way to connect to both God and man trough the ethical precepts of Torah.
It is important for Jews to participate in repairing the world by participating in tzedakah (justice and righteousness) and g'milut hasadim (acts of loving kindness). Without our stake in the improvement of our world, injustice and evil will continue to exist.
As the prophet Micah so succinctly stated when he summed up God’s Torah : What does God require of you, Do justly, love mercy and walk humbly with your God.