How can one repent and remain steadfast when repeatedly committing grave sins, and can such a person be considered among the repentant wrongdoers?

A Muslim must repent to Allah for all sins, for Allah forgives sins no matter how great, as long as the servant turns to Him with his heart and rectifies his repentance. One who repents from sin is like one who has no sin. A Muslim must not persist in committing sins, because persistence in a minor sin makes it a major one. Among the signs of true faith is that one's good deed pleases him and his evil deed grieves him. The true fear of Allah is what prevents one from committing Allah's prohibitions. Thus, the path of repentance lies in steadfastness in obeying Allah, abandoning disobedience to Him, and not persisting in sin, for the best of sinners are those who repent.