Allah's right upon His servants is that they should worship Him and associate no partners with Him. And the right of the servants upon Allah is that He should not punish whoever associates no partners with Him

Mu‘ādh (may Allah be pleased with him) reported:

I was riding behind the Prophet (may Allah’s peace and blessings be upon him) on a donkey called ‘Ufayr. The Prophet (may Allah’s peace and blessings be upon him) asked: "O Mu‘ādh, do you know what Allah's right upon His servants is, and what the right of His servants upon Him is?" I replied: "Allah and His Messenger know best." He said: "Allah's right upon His servants is that they should worship Him and associate no partners with Him. And the right of the servants upon Allah is that He should not punish whoever associates no partners with Him." I said: "O Messenger of Allah, should I not inform the people of this good news?" He said: "Do not inform them of it, lest they depend on it solely."

كُنْتُ رِدْفَ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ عَلَى حِمَارٍ يُقَالُ لَهُ عُفَيْرٌ، فَقَالَ: «يَا مُعَاذُ، هَلْ تَدْرِي حَقَّ اللَّهِ عَلَى عِبَادِهِ، وَمَا حَقُّ العِبَادِ عَلَى اللَّهِ؟»، قُلْتُ: اللَّهُ وَرَسُولُهُ أَعْلَمُ، قَالَ: «فَإِنَّ حَقَّ اللَّهِ عَلَى العِبَادِ أَنْ يَعْبُدُوهُ وَلا يُشْرِكُوا بِهِ شَيْئًا، وَحَقَّ العِبَادِ عَلَى اللَّهِ أَنْ لا يُعَذِّبَ مَنْ لا يُشْرِكُ بِهِ شَيْئًا»، فَقُلْتُ: يَا رَسُولَ اللَّهِ أَفَلاَ أُبَشِّرُ بِهِ النَّاسَ؟ قَالَ: «لا تُبَشِّرْهُمْ، فَيَتَّكِلُوا».