Doubt, indulged and cherished, is in danger of becoming denial; but if honest, and bent on thorough investigation, it may soon lead to full establishment of the truth.
A man was meant to be doubtful about himself, but undoubting about the truth; this has been reversed. Nowadays the part of a man that a man does assert is exactly the part he ought not to assert - himself. The part he doubts is exactly the part he ought not to doubt - the Divine Reason.
The majority of mankind is lazyminded, incurious, absorbed in vanities, and tepid in emotion, and is therefore incapable of either much doubt or much faith.
The probability that we face global warming caused by fossil fuels is now so overwhelming that it is legitimate to doubt the motives of those who deny it
Given the millions of billions of Earth-like planets, life elsewhere in the Universe without a doubt, does exist. In the vastness of the Universe we are not alone.
It's murder to doubt yourself in life. It took until I was 45 to get to that point. As hard as it is in your work, it's harder in your life. But it can be done.
Satisfy yourself beyond all doubt that you are qualified for the course to which you now aspire.....and try to achieve something in your own land before you venture on a strange one.