Are the 21 Coptic Christians, who lost their lives for their faith, in heaven because they were martyred (greater love hath no man), or in hell because they are not sola fides, sola scriptura, self-Bible-interpreting “born-again” people who say they follow Jesus?
Depends. If they believed they had earned their salvation by their own merits, then they are in hell, for they have no merits except what is given to them from above.
If they believed in their heart of hearts that they were unworthy of heaven and of the glory of martyrdom, then they are surely in heaven.
Luk 18:10 Two men went up into the temple to pray; the one a Pharisee, and the other a publican. Luk 18:11 The Pharisee stood and prayed thus with himself, God, I thank thee, that I am not as other men are, extortioners, unjust, adulterers, or even as this publican. Luk 18:12 I fast twice in the week, I give tithes of all that I possess. Luk 18:13 And the publican, standing afar off, would not lift up so much as his eyes unto heaven, but smote upon his breast, saying, God be merciful to me a sinner. Luk 18:14 I tell you, this man went down to his house justified rather than the other: for every one that exalteth himself shall be abased; and he that humbleth himself shall be exalted.