Praise be to Allah.
Among the obstacles to marriage is the lack of money and sometimes the dowries are too high.
Most young people have the stage of marrying, they don’t want to commit haraam acts. However, they are going through a difficult time and are afraid of committing Al Zina.
May Allah forbid.
Can they take money from a bank (mostly with interest) to build a house and get married? Or what should they do to overcome the obstacles to marriage?
First of all, you indeed know that the Prophet (blessings and peace of Allah be upon him) advises young men who can afford marrying to get married.
Similarly, Islam did not forget those who cannot afford it and are advised in the Sunnah to fast, so they can attain taqwa (mindfulness of Allah). This will protect them from committing haraam actions and teach them good manners and behaviour.
The following Hadiths will prove the advice from the Quran and Hadiths for Young people on many obstacles to marriage.
It was narrated that ‘Abdullah ibn Mas‘ood said: We were with the Prophet (blessings and peace of Allah be upon him) when we were young and had nothing with which to get married.
The Messenger of Allah (blessings and peace of Allah be upon him) said to us: “O young men, whoever among you can afford it, let him get married, for it is more effective in lowering the gaze and guarding one’s chastity. And whoever cannot afford it should fast, for it will be a shield for him.”
Narrated by al-Bukhaari (4779) and Muslim (1400).
Allah, may He be exalted, says:
“But let them who find not [the means for] marriage abstain [from sexual relations] until Allah enriches them from His bounty” – [An-Noor 24:33].
“And do not approach unlawful sexual intercourse. Indeed, it is ever an immorality and is evil as a way” – [al-Israa’ 17:32]
To Point out some other relevant pieces of advice;
The young people who do not have enough money to get married should work harder to attain the means of getting married.
He could also borrow from someone else to get married, for Allah, may He be exalted, has promised to help the one who wants to get married to remain chaste.
In short, though the obstacles to marriage for young people is much, while the primary reason could be money.
Don’t forget that, taking riba-based loans from the bank is haraam. Using such loans to build a house or getting married is not a legitimate shar‘i excuse.
And Allah knows best.