Is it possible to justify watching pornography and masturbating by claiming that a human is not infallible, or that these are minor sins expiated by acts of worship such as prayer and fasting, or that they are part of one's destiny as a written form of adultery?

A Muslim must hasten to repentance and seek forgiveness upon falling into sin, for persistence in sin is the problem. Allah has mentioned the characteristics of the righteous and the good-doers, stating that when they commit an indecency or wrong themselves, they remember Allah and seek forgiveness for their sins. He also mentioned that they avoid major sins, except for al-lamam, which are minor sins that a servant does not persist in. It is authentically reported in a hadith that every son of Adam is a sinner, and the best of sinners are those who repent. Thus, a believer repents, then forgets and relapses, then remembers and repents again. The recurrence of sin and repentance indicates the acceptance of repentance, no matter how often it recurs. As long as the servant regrets his sin and hastens to repent and seek forgiveness, it is a good matter. One must avoid justifying sin by claiming it is merely lamam, or that one is not infallible, or that good deeds atone for bad deeds, as these justifications may lead to persistence in sin.