So now that I have answered you, will answer why the topic of this thread is necessary for salvation?
It is necessary that one not deny divinely revealed truth. The one holy catholic apostolic church declared as dogma (a fundamental of the faith) the Unity and Trinity of God. If someone who is a baptized Christian publicly denies the Holy Trinity, such a one has departed from the faith and is a heretic. These things write I unto thee, hoping to come unto thee shortly: But if I tarry long, that thou mayest know how thou oughtest to behave thyself in the house of God, which is the church of the living God, the pillar and ground of the truth. It is a faithful saying: For if we be dead with him, we shall also live with him: If we suffer, we shall also reign with him: if we deny him, he also will deny us: If we believe not, yet he abideth faithful: he cannot deny himself. Of these things put them in remembrance, charging them before the Lord that they strive not about words to no profit, but to the subverting of the hearers. Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth. But shun profane and vain babblings: for they will increase unto more ungodliness. And their word will eat as doth a canker: of whom is Hymenaeus and Philetus; Who concerning the truth have erred, saying that the resurrection is past already; and overthrow the faith of some. Nevertheless the foundation of God standeth sure, having this seal, The Lord knoweth them that are his. And, Let every one that nameth the name of Christ depart from iniquity. But in a great house there are not only vessels of gold and of silver, but also of wood and of earth; and some to honour, and some to dishonour. If a man therefore purge himself from these, he shall be a vessel unto honour, sanctified, and meet for the master's use, and prepared unto every good work. Flee also youthful lusts: but follow righteousness, faith, charity, peace, with them that call on the Lord out of a pure heart. But foolish and unlearned questions avoid, knowing that they do gender strifes. And the servant of the Lord must not strive; but be gentle unto all men, apt to teach, patient, In meekness instructing those that oppose themselves; if God peradventure will give them repentance to the acknowledging of the truth; And that they may recover themselves out of the snare of the devil, who are taken captive by him at his will.
First Timothy, Catholic chapter three, Protestant verses fourteen to fifteen,
Second Timothy, Catholic chapter two, Protestant verses eleven to twenty six,
as authorized, but not authored, by King James