Why do Catholics fight the idea of the security of the believer so hard?
Why don’t they seem to want to believe that God will keep secure those who trust in Him?
Why do they feel the need to contribute to their salvation so much?
I don’t get the mindset of a person who wants to believe so hard that he could lose his salvation.
I would think Catholics, at least those who are spiritual, would fight for the security of the believer by obeying the scripture But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin.. Read the scriptures I posted where the LORD and his apostles plead with us for our benefit and security. All we have to do is willingly trust and obey.
Why don’t they seem to want to believe that God will keep secure those who trust in Him?
He will keep secure those who trust in Him, not those who trust in OSAS. He gets to define what "trust in Him" means and it is to continue in the faith. Never give up. Cling to him because you love him and you will obey him. Remember the woman who washed Jesus' feet with her tears.
Why do they feel the need to contribute to their salvation so much? Wherefore seeing we also are compassed about with so great a cloud of witnesses, let us lay aside every weight, and the sin which doth so easily beset us, and let us run with patience the race that is set before us, 2Looking unto Jesus the author and finisher of our faith; who for the joy that was set before him endured the cross, despising the shame, and is set down at the right hand of the throne of God. For consider him that endured such contradiction of sinners against himself, lest ye be wearied and faint in your minds. Ye have not yet resisted unto blood, striving against sin. And ye have forgotten the exhortation which speaketh unto you as unto children, My son, despise not thou the chastening of the Lord, nor faint when thou art rebuked of him: For whom the Lord loveth he chasteneth, and scourgeth every son whom he receiveth. If ye endure chastening, God dealeth with you as with sons; for what son is he whom the father chasteneth not? But if ye be without chastisement, whereof all are partakers, then are ye bastards, and not sons. Furthermore we have had fathers of our flesh which corrected us, and we gave them reverence: shall we not much rather be in subjection unto the Father of spirits, and live? For they verily for a few days chastened us after their own pleasure; but he for our profit, that we might be partakers of his holiness. Now no chastening for the present seemeth to be joyous, but grievous: nevertheless afterward it yieldeth the peaceable fruit of righteousness unto them which are exercised thereby. Wherefore lift up the hands which hang down, and the feeble knees; And make straight paths for your feet, lest that which is lame be turned out of the way; but let it rather be healed.
It is the mindset of a person who, because of the word of grace and truth from the Holy One of Israel, turns from sin to believe and love the LORD his God with all his heart, all his soul, and all his strength; and his neighbor as himself; and the brethren, who are blessed Mary the mother of God with us and the blessed Apostles who gave their lives in service and martyrdom for our benefit out of their great love and submission, all of which constrains him to the holy scriptures and the holy catholic apostolic church built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner stone;