Will a person be exposed on the Day of Judgment because of his major sins, and is a less observant Muslim afflicted with sin so that he may draw closer to God?

If you repent with sincere repentance, Allah will accept your repentance and forgive your sin, and you will be as if you had never sinned. Have a good opinion of your Lord and know that He is Forgiving and Merciful, as He (the Most High) said: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" Allah will not expose you on the Day of Resurrection, nor will He hold you accountable for this sin. Strive in acts of obedience and good deeds, for they expiate evil deeds.