It is narrated from Hazrat Abu Hurairah (may Allah be pleased with him) that the Holy Prophet (peace and blessings of Allah be upon him) said: In the sight of Allah, a strong believer is better, superior, and more beloved than a weak believer, and there is goodness in each. Strive for those things that benefit you and do not become helpless. If any matter overpowers you, then say: "Allah has decreed it thus, and Allah does what He wills." And protect yourself from "if" and "but," for "if" and "but" open the door of Satan.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 8829
Hadith Gradingحکم دارالسلام:حديث حسن، وقد اختلف فى إسناده، م: 2664