I'm a Thomist. Catholic Christians, like me, generally go with St. Augustine and St. Thomas - two imo of the Greatest Theologians who ever lived - on such deep matters of Theology. (1) God gives all Sufficient Grace to be saved. (2) When man consents to God, God Himself deserves the Glory for this. (3) Predestination to Grace, or Adoption, is entirely Gracious/Undeserved/Unmerited. (4) Once placed in the State of Grace, or having received the Indwelling of the Holy Spirit, by faith in Christ as Lord and Savior, man can then do Good Works deserving/earning merits/rewards. This has always been understood as those Treasures in Heaven the Lord told us to store in Mat 6: "Store your Treasures in Heaven". (5) The Grace of Final Perseverance, which confirms and preserves us in the Faith, is also Gracious and Unmerited. After Justification, we must patiently Pray, do Good Works, Love God and our Neighbor, Forgive, even our enemies, and wait for this Grace. In due time, this Second Grace, of Perseverance, after Justification, which we ask for in the Lord's Prayer, will be given, and after that, we will never fall away from the Faith, and thus receive complete salvation, and go to Heaven when we die. See Rom 2:6-7 also.
After reading many Bible texts, I find this imo to be the best summary. But, the Good News is, we don't need to be Theologians to be saved. Let's not rashly anathematize or excommunicate each other imo. But explain what we find convincing and why. I like the above view also because it challenges and motivates me to give my best for the Lord Jesus.
God Bless.