Regrets begin with the choic e of whom you

Some people might think that being allies with disbelievers is simply an ordinary relationship; the Quran, however, makes a distinction between treating them with justice and kindness, and making of them allies to whom the heart is subservient, while trying to please them instead of pleasing Allah, or supporting their falsehood.
Hence, the warning is clear: “O you who have believed, if you obey those who disbelieve, they will turn you back on your heels, and you will [then] become losers.” [Al-Imran: 149]
People are influenced by those they trust and take as an example to follow, only to eventually find themselves drifting away from the truth, slowly. The Quran depicts the painful end of this path:
“Oh, woe to me! I wish I had not taken that one as a close friend.” [Al-Furqan: 28]

It is a state of despair that cannot be remedied by wishes, when people find out that those they followed in this world will not bear any of their burdens on the Day of Judgment.
Therefore, make sure that your alliance be with Allah, His Messenger, and the believers. Choose those people who help you in obedience; for a companion is a path, allegiance is a matter of belief, and regret serves no purpose once it is too late