It was narrated on the authority of Abu Hurayrah, may Allaah be pleased with him, that the Prophet, sallallaahu ‘alayhi wa sallam, said: “A woman is married for four (reasons): her wealth, noble ancestry, beauty and religion. Choose the religious woman lest your hand is stuck to dust (because of destitution).” [Al-Bukhaari and Muslim]
So this shows us, that it becomes incumbent to search ONLY PIOUS spouses. Now the big question remains, HOW?
Allah knows best! These are the steps usually recommended:
STEP 1: DUA, There is nothing more powerful then a DUA, so ask Allah sincerely to grant a righteous spouse
STEP 2: Before you see the girl or boy, see the environment he/she has been growing up. You are a product of your environment, if the family is not pious and righteous, you can’t expect the girl/boy to be righteous (in most cases)
STEP 3: Look for good character
The Prophet (saw) said:
“When someone with whose religion and character you are satisfied asks your daughter in marriage, accede to his request. If you do not do so, there will be temptation on Earth and extensive corruption.“
[Tirmidhi, Nasa'i & Ibn Majah]
STEP 4: Ask for references
A reference can include an Imam who knows the brother who proposed to you, a sister who knows the woman you may want to marry well, a family friend, a boss, a co-worker, and/or business partner.
A note about honesty and references: the people you ask may know something not very nice about your prospective spouse. Remind them that if they reveal this information, they would not be backbiting from the Islamic perspective. In fact, in the case of seeking marriage, complete information should be given about an individual, both good and bad.
The advice of one of the companions of the Prophet, Umar Ibn al-Khattab, can help in this regard:
A man came to Umar ibn al-Khattab and spoke in praise of another. Umar asked him: “Are you his nearest neighbor such that you know his goings and his comings?”
“Have you been his companion on a journey so that you could see evidence of his good character?”
“Have you had dealings with him involving dinars and dirhams [money] which would indicate the piety of the man?”
“I think you saw him standing in the mosque muttering the Quran and moving his head up and down?”
“Go, for you do not know him...”
And to the man in question, Umar said, “Go and bring me someone who knows you.”
STEP 5: Pray Istikharah.