The definition of discriminate in it's purest form is to differentiate. This can mean you can discriminate between good quality and bad quality. The word is often use to describe someone's taste. She has very discriminating taste. Used in this way, the word is a compliment.
But, when folks start differentiating based on race, religion, looks, socio-economic class, politics, etc, we start having problems. Is it showing discriminating taste to not allow people that are different from you to feel included or welcome? I think that when you are in the group that is making the decisions it might feel empowering. You might feel like you are popular so you get to choose. Usually when I find myself in situations where we have to exclude anyone, I feel a little uncomfortable.
Sometimes situations come up and not everyone can be included. There are only 6 seats in my van, so only 5 other knitters can ride with me to the Fold. If I leave you out, am I discriminating against you? I guess it would depend on the criteria for the selection. I tend to be of the first come first served philosophy to avoid using any other criteria, because I don't want to hurt anyone's feelings.
If in knitting club, for example, there is a decision being made about something that impacts the entire group, then the decision should not exclude anyone in the group. It is not ok to say, you may come for part of the meet-up, but you can not stay for the whole thing, because making sure the activity in inclusive isn't important to us. Essentially, if you are saying the club wants to do something, and the majority of folks are ok with it, then you have to get on board, will exclude minority groups. You may not like the minority group. You may not agree with their opinions, but if you differentiate between one group and another you are discriminating.
Apply this rule to your life, have you ever made a decision that excluded one group/person? Did you make that based on religion, politics, socio-economic class, etc? If you made the decision to exclude someone based on say, religion, you have discriminated. But, only you can know your reasoning for the decision, insert your reason, and it may be that you have discriminated. In our culture, discriminating against a group based on religion, socio-economic status, race, etc, can put you in the position of being called a bigot.
I am not asking you to out yourself. I am not asking you to tell anyone, but I am asking you to look long and hard at your behavior and think, do I discriminate? If so, am I a bigot? If the answer is yes, and I would find it hard to believe that it isn't, think about what you can do to right the situation. None of us is perfect, and we all have biases. I know that I make decisions that could be classified as discriminating, and not in the good way. I try not to, but I am not perfect.
Finally, it is my opinion that if you did discriminate you did something wrong. Judgment aside, saying you are sorry you hurt someone's feelings does not mean you have to acknowledge you did something wrong, only that you are sorry that they are hurt by the situation. If you did do something wrong, and you recognize that, it is also a good thing to acknowledge your part in the situation. But, some people don't realize that their actions are hurtful, so they don't know that they were part of the situation. This is why I am so big on saying sorry, even if you don't think you did anything wrong. Trust me, it will go along way.