The criteria to go to Jannah:-

It is mentioned in Surah Al Asr 103: verses 1-3

By time,

Indeed, mankind is in loss,

Except for those who have believed and done righteous deeds and advised each other to truth and advised each other to patience and perseverance.

For any human being to go to Jannah, minimum 4 criteria are required.

1. Having Faith/ Imaan

2. Righteous deeds

3. Inviting people to truth

4. Inviting people to patience and perseverance.

If Allah wishes, He may forgive any sin but the sin of shirk(Associating partners with Allah), He never forgives.

Allah says in Surah Nisa 4:48

Indeed, Allah does not forgive association with Him, but He forgives what is less than that for whom He wills. And he who associates others with Allah has certainly fabricated a tremendous sin.

Surah Nisa 4:116

Indeed, Allah does not forgive association with Him, but He forgives what is less than that for whom He wills. And he who associates others with Allah has certainly gone far astray.

The fruit of Steadfastness:-

Surah Al-Anam 6:126,127

And this is the path of your Lord, [leading] straight. We have detailed the verses for a people who remember.

For them will be the Home of Peace with their Lord. And He will be their protecting friend because of what they used to do. When the servant becomes steadfast, he is given glad tidings to enter the abode of peace (Dar us Salam).

Surah An-Nisa 4:131

And to Allah belongs whatever is in the heavens and whatever is on the earth. And We have instructed those who were given the Scripture before you and yourselves to fear Allah . But if you disbelieve - then to Allah belongs whatever is in the heavens and whatever is on the earth. And ever is Allah Free of need and Praiseworthy.

Allah says in the Hadith al Qudsi , O My servants, if the first of you and the last of you, and humans of you and the jinn of you, were all as wicked as the most wicked heart of any individual amongst you, then this would not decrease My Kingdom an atom. This is the proof that Allah Subhanahu ta’la is Self- Sufficient.

O My servants, if the first of you and the last of you, and the humans of you and the jinn of you, were all as pious as the most pious heart of any individual amongst you, then this would not increase My Kingdom an atom.

We need to remain steadfast, just as Allah ordered us. This is only for our benefit.

Surah Al-Jumuah 62:9

O you who have believed, when [the adhan] is called for the prayer on the day of Jumu'ah [Friday], then proceed to the remembrance of Allah and leave trade. That is better for you, if you only knew.

Allah ordered us to worship Him , He is not in need of worship. Allah is Self Sufficient one (Al Ghani) .

Allah says in the following verse.

Surah Al- Anam 6:153

And, [moreover], this is My path, which is straight, so follow it; and do not follow [other] ways, for you will be separated from His way. This has He instructed you that you may become righteous.

The scholars defined steadfastness as remaining on the straight path without deviating from it, not to the right nor left, to worship Allah alone as He commanded. Lets leave what is unlawful and lets remain steadfast till death until we meet Allah. The End of this Earth comes when it has to come, but we should not forget, our end is when we die.

May Allah Subhanahu Ta'la make us from those who will enter Paradise. In sha Allah.