Believer Should Be Constantly Preparing Himself For The Aakhirah – [A Brief Admonition By Imaam Abdul Azeez Bin Baaz]
In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Abdullaah Ibn Umar (radiyallaahu-anhumaa) said, ”Allaah’s Messenger (sallal-laahu-alayhi-wasallam) took hold of my shoulder and said: ‘Be in this world as if you were a stranger or a traveller.” Ibn Umar used to say: ”If you survive till the evening, do not expect to be alive in the morning, and if you survive till the morning, do not expect to be alive in the evening, and take from your health for your sickness, and (take) from your life for your death.
Imaam Abdul-Azeez Bin Baaz (rahimahullaah) said: This is a tremendous affair because the stranger (in a land) has no concern (for anything else) except with the affairs of travel, therefore let those in the worldly life prepare (themselves). This is what is befitting the believer–he (or she) should be a stranger because the stranger (in a land) prepares for travel. Likewise, this is how the sensible person should be in a (state of) preparedness and cautiousness. 
 Book of Ar-Riqaaq. Saheeh Bukhaari Vol 8. Hadeeth No: 6416. Pages: 234-235. Daarus Salaam
 Al-Hulalul Ibreeziyyah Min At-taliqaat Al-Baaziyyah Alaa Saheeh Al-Bukhaariy. Page: 223; Vol: 4. abridged & slightly paraphrased]