Is it permissible to entice and endear people to deeds that have multiplied rewards by using a title such as: "How to increase your lifespan" or "Deeds that increase lifespan," intending that these deeds increase reward and recompense in a way that cannot be attained within a limited lifespan?

It is permissible to use titles such as "Deeds that Increase Life" to encourage good deeds, whether the increase is tangible, like maintaining kinship ties, or intangible, like deeds with multiplied rewards. The Prophet (peace be upon him) used this approach.

According to Sheikh Al-Albani, the increase in life due to maintaining kinship ties and other good deeds is a real increase, and it does not contradict the fact that one's lifespan is predetermined, because Allah has made these deeds legitimate causes for a longer life. Causes do not contradict what is written in the Preserved Tablet, just as faith increases and decreases.

Deeds with multiplied rewards are considered an intangible increase in life. For example, Laylat al-Qadr (the Night of Decree) is better than a thousand months, which means that performing deeds on it is equivalent to long lifespans.

Based on this, there is no harm in using this method in calling to deeds for which an increase in life has been proven, whether literally or figuratively.