Among The Means To Tasting The Sweetness of Imaan
Abbaas Bin Abdul Muttalib [radiyallaahu-anhu] said that he heard Allaah’s Messenger [sallal-laahu-alayhi-wasallam] saying:
ذَاقَ طَعْمَ الإيمَانِ مَنْ رَضِيَ بِالله رَبّا وَ باْلإِسْلاَمِ دِيناً و بِمُحَمّدٍ رسولا
“The one who pleased that Allah is his lord and Islam is his religion and Muhammad is his messenger shall taste the sweetness of Imaan.”
The meaning of the Hadeeth is that he [or she] only seeks the [pleasure of] Allaah-The Most High .
He [or she] does not follow other than the path of Islaam and does not follow except that which is in agreement with Muhammad’s [sallal-laahu-alayhi-wasallam] Sharee’ah. 
There is no doubt that the sweetness of Eemaan becomes pure in the heart of one with these qualities and indeed he [or she] has [definitely] tasted its sweetness.
[Refs 1& 3: Source: Imdaadul Muslim Bi-Sharh Mukhtasar Al-Mundhiri Li-Saheehi Muslim. Vol 1. Page: 170 By Shaikh Ubaid Al-Jaabiri (may Allaah preserve him) – Slightly paraphrased]
[Ref 2: For more benefits from this hadeeth, see [مدارج السالكين- 2/171. By Imaam Ibnul Qayyim (rahimahullaah)]