Amen! I watched a Fr. Corapi sermon on EWTN last night (Mom asked me to) and I heard him say the following, "Without humility there is no holiness. Without holiness there is no heaven."
Now I think we can all agree that this is a true statement. The problem is, how do we get holiness? The Catholic Curch teaches only the sacraments of the Church give the grace that makes us holy. So if one does not receive the sacraments, they cannot become holy and will not go to heaven. Yet, scripture is so clear that the holiness God requires for entrance into heaven is HIS righteousness. We must be as righteous as God - as holy as he is - and there is no way we can ever attain this perfection no matter how many rosaries we say, how many masses we attend, how many good deeds we perform.
Without Christ dying in our place to pay the price of our sins, there could be no holiness possible for us. That is why we are found "in him" not having our own righteousness but the righteousness which is of God THROUGH faith IN CHRIST.
I watched a Fr. Corapi sermon on EWTN last night (Mom asked me to)...You have a very smart mother ... tell her I'll say a decade for her tomorrow ...
Below is pasted just a portion of what the Catechism of the Catholic Church teaches about how “we get holiness,” and I post it without further comment (and before jumping off the thread for the night) merely in an attempt to respond to the question you raised:
2017 The grace of the Holy Spirit confers upon us the righteousness of God. Uniting us by faith and Baptism to the Passion and Resurrection of Christ, the Spirit makes us sharers in his life.
2018 Like conversion, justification has two aspects. Moved by grace, man turns toward God and away from sin, and so accepts forgiveness and righteousness from on high.
2019 Justification includes the remission of sins, sanctification, and the renewal of the inner man.
2020 Justification has been merited for us by the Passion of Christ. It is granted us through Baptism. It conforms us to the righteousness of God, who justifies us. It has for its goal the glory of God and of Christ, and the gift of eternal life. It is the most excellent work of God’s mercy.
2021 Grace is the help God gives us to respond to our vocation of becoming his adopted sons. It introduces us into the intimacy of the Trinitarian life.
2022 The divine initiative in the work of grace precedes, prepares, and elicits the free response of man. Grace responds to the deepest yearnings of human freedom, calls freedom to cooperate with it, and perfects freedom.
2023 Sanctifying grace is the gratuitous gift of his life that God makes to us; it is infused by the Holy Spirit into the soul to heal it of sin and to sanctify it.
2024 Sanctifying grace makes us “pleasing to God.”
The Catholic Church does NOT teach that the sacraments are the only way to obtain divine grace. They are the normative way of obtaining grace. A person is under the obligation to receive the sacraments if it is at all possible
However, in certain exceptional cases you can receive saving grace without the reception of the sacraments. For instance, if a person is invincibly ignorant they can be saved without water baptism. If a person is not baptized, but has faith and love for God they can be saved by baptism of desire or the baptism of blood. If a person is a baptized Catholic that has committed a mortal sin and dies without going to confession, they can receive saving grace, but only if they had perfect contrition at the time of their death. (Perfect contrition is a sorrow for sin based solely on the love of God rather than fear of punishment). However, these are special exceptions for extenuating circumstances, and in all normal circumstances God intends that the reception of the sacraments in order for people to receive the grace associated with them.
The problem is, how do we get holiness?
I think as you correctly noted, it is impossible for us to become Holy on our own. We can never merit it ourselves. The only way for us to become Holy is by the Grace of God obtained through the blood of Jesus Christ. It is the Grace given through the blood of Jesus Christ that makes us Holy. So your question can be rephrased from "What make's us Holy" to "how do we obtain Grace?" I don't know how the Council of Trent defines the exact nature of the relationship of Works and Faith, but cannot doubt that God will save you if you believe in God and Jesus Christ and love Him. So there you have it, as it seems to me. At the core, it is a person's belief in and love of God that ultimately enables God to make us Holy and save us through His Son's Sacred Blood.