The three that show up regardless of what is claimed
None of them is about belief.
آيَةُ الْمُنَافِقِ ثَلاَثٌ إِذَا حَدَّثَ كَذَبَ، وَإِذَا وَعَدَ أَخْلَفَ، وَإِذَا اؤْتُمِنَ خَانَ
Āyatu-l-munāfiqi thalāth: idhā ḥaddatha kadhab, wa idhā waʿada akhlaf, wa idhā-ʾtumina khān
The sign of the hypocrite is three: when he speaks he lies, when he promises he breaks it, and when he is trusted he betrays.
Where this comes from
All three are about the gap between what was said and what happened. It is a test that can be applied from outside, which is what a sign is for.
The full narration
Narrated Abu Huraira: The Prophet (ﷺ) said, "The signs of a hypocrite are three: 1. Whenever he speaks, he tells a lie. 2. Whenever he promises, he always breaks it (his promise ). 3. If you trust him, he proves to be dishonest. (If you keep something as a trust with him, he will not return it)
Source
Ṣaḥīḥ al-Bukhārī · 33
- Agreed upon as authentic (al-Bukhārī / Muslim)