Some are going to be seduced by false spirits. They may or may not repent. Whether they repent and press forward to be ministered to by a messenger from God, and then find God, will depend on how closely they follow truth and light. False spirits prop up egos and pride. Anything of that sort will lead to darkness.
True messengers and true messages conform to a pattern: "Behold, that which is of God inviteth and enticeth to do good continually; wherefore, every thing which inviteth and enticeth to do good, and to love God, and to serve him, is inspired of God." (Moroni 7: 13.) More importantly, they have a central focus that will NEVER change: "Every thing which inviteth to do good, and to persuade to believe in Christ, is sent forth by the power and gift of Christ; wherefore ye may know with a perfect knowledge it is of God. But whatsoever thing persuadeth man to do evil, and believe not in Christ, and deny him, and serve not God, then ye may know with a perfect knowledge it is of the devil[.]" (Moroni 7: 16.)
Any preacher, leader, bishop, president, apostle, seventy or elder who asks you to believe in men, trust men, accept authority of men, is most certainly not of Christ. (See D&C 76: 99-101.) Anyone who points you to Christ, asks you to seek to know Christ, invites you to struggle to hear and follow Christ, you can know is of Christ.
Those who boast of their own spiritual prowess as a credential to have you notice them are dangerous. Those who testify of Christ, preach of Christ and ask you to know Him, while admitting their own insignificance, are worth hearing. Everything I believe is anchored in the scriptures.
Those who are deceived as they struggle to find Christ can repent as soon as they realize they have listened to a false spirit. Joseph was overcome by "thick darkness" before he called upon God and was delivered. Lehi walked behind a man dressed in white for the space of many hours in a "dark and dreary waste" before he called upon God and was delivered. When Adam built an altar and called upon God, it was Lucifer who replied, "I hear you, what is it you want?" Adam had to refuse the offer and await true messengers sent from the Father.
You will encounter false spirits, as well as true ones if you will persist. You need to be familiar with both in order to choose. These opposing forces are part of the process of becoming competent and adept. No one lacking knowledge of these things can be saved. "A man is saved no faster than he gets knowledge, for if he does not get knowledge, he will be brought into captivity by some evil power in the other world, as evil spirits will have more knowledge, and consequently more power." (TPJS, p. 217.)
Do not fear learning and experience. Fear ignorance. Ignorance will damn you.