"… and My Mercy embraces all things.” [7:156]
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." [39:53]
Peace.
Disobedience to Allah comes generally from forgetfulness, ignorance, shear arrogance and laziness. All these causative agents constitute the materials, by which man was built. It's man's nature!
Undoubtedly, it is part of the human nature to forget, be arrogant and lackadaisical with instructions coming from whomever, especially entities who aren't cognitive authorities over them. Well, one other side of the coin is the realization that the entity or entities are in fact, cognitive authorities. A third side is the will power to do just as instructed.
For us Muslims, we submit fully to the instructions of Allah, realizing that He possesses all kinds of authority over us, as our Lord and us, His humble servants. That is the basics. That is basically what it means to be Muslim. And that is the basis for the instructions that follow. A servant would obey His master.
These traits continue to chase us even though we are still. But since it is natural to possess these traits, it then becomes difficult to restrain oneself from them and hence, from disobedience to Allah.
Rather than run away from them from unknown to no where, it is better to employ a control mechanism - Islam in other words. The sole reason why we take to control these traits is because we are Muslims - people who submit fully and willfully to Allah's will.
But how strong is our hold to this "control mechanism"? So we falter all the time. And hence, seek forgiveness for He is most forgiving and "...(His) My mercy embraces everything"
As often as we falter and disobey, and no matter how massive our disobedience is, we are encouraged to seek Allah's forgiveness and strive to not go back to it (or them).
Muslims are hopeful people. They are hopeful that Allah, the all forgiving would forgive them, no matter how much they have transgressed the limits He set for them so they seek His forgiveness. They are also fearful of Allah's punishment so the practice self restraint and refrain from doing all acts of disobedience. They do not despair of the mercy of Allah the often forgiving as in the verse 53 of chapter 39 of the Quran stated in the beginning of this article.
No one enters Jannah by the amount of work he puts in but by Allah's infinite mercy. All the work and striving tends to pleasing Allah and seeking His face. The Muslim is urged to be always hopeful of Allah's mercy and fearful of His punishment - moderate and in between the two extremes.
Don't ever despair of Allah's mercy. No matter what you've done. No matter how shameful it is. Allah created you. Allah Has said He would forgive you so long as you seek His forgiveness. There isn't any sin Allah won't forgive you for. All you need to do is seek His forgiveness sincerely, feel remorseful about it and resolve to never go back to it.