Praise be to Allah.
There is nothing to prevent a person from making plans and estimating what he will need in the future, and thinking of what he hopes to achieve, or saying, ‘I will do such-and-such tomorrow,’ or next week, or next year.’ But when he does that he has to say ‘in sha Allaah (if Allaah wills).’ Allaah says (interpretation of the meaning):
“And never say of anything, ‘I shall do such and such thing tomorrow,’ except (with the saying): ‘If Allaah will.’…”
Everything that a person intends to do in the future, or resolves to do, or hopes to achieve, is based on hope, and hope is what motivates people to do things. But the believer strives in this world for the sake of that which will benefit him in both his religion and his worldly affairs. So he takes the means and puts his trust in Allaah, and seeks His help, as the Prophet (peace and blessings of Allaah be upon him) said:
“Strive to do that which will benefit you, and seek the help of Allaah.”
And Allaah says (interpretation of the meaning):
“… So worship Him and put your trust in Him…”
The kaafir and the negligent person, on the other hand, depend on the means and forget their Lord in Whose Hand is Sovereignty and nothing happens except what He wills. If a man looks at the obstacles which stand between him and what he hopes for, and he thinks too much about death and other obstacles, he will stop making efforts and neglect his own interests. Thus it is apparent that man cannot live this life without some hope which will make him strive to pursue the things that he wants to achieve. But the believer should not hope for too much or feel too content with this world, or prefer its pleasures; rather he should strive to make the Hereafter his goal, and work to do righteous deeds which will bring him closer to his Lord, and seek the help of His blessings to obey Him, so that he may attain happiness in this world and in the Hereafter.