Growing up at a private Christian school, it was very easy for me to only have friends who believe the exact same way that I do. Almost all of us grew up in Church with Godly parents who were trying their best to teach us and help us to learn what it means to have a personal relationship with Christ. And, don't get me wrong, I cherish that and there's not a doubt in my mind that made me who I am today. The Bible makes it very clear that our friends and who we surround ourselves with are important.
"Bad company corrupts good character." 1 Corinthians 15:33
However, when I went to college, I was thrown into a world much bigger and more diverse than my little school with only 68 people in my graduating class. I was exposed to a thousand different kinds of people, who all believed differently than I do. I do believe that your closest friends should encourage you in the Faith, build you up, and challenge you to grow closer in your walk with the Lord; however, my exposure to different views has changed my heart on the issue of being friends with non-believers.
It is important to have friends that DON'T have the same beliefs and values as yourself.
If you only have Conservative, Republican, Baptist friends:
1- You don't have an opportunity to witness... By being friends with someone who has different views than you do, you are able to show them that not all Christians are the stereotypical close-minded, judgmental, holier-than-thou people that the media tries to make us out to be.
Yes, I have very different views on gay marriage, abortion, and several other moral issues than some of my friends, but that doesn't get in the way of our friendship because we are able to understand that we grew up differently and have encountered life experiences that have molded the way we view things. A nonChristian can be greatly impacted if a Christian doesn't condemn them.
*Please note: if someone with different views does allow your differences to get in the way of your friendship, you just have to recognize that they are at a different place in their life and are not at the level of maturity to form relationships outside of their own worldview. Pray for them.
2- You aren't able to fully understand the other side of the equation. In order to effectively understand apologetics, you must understand both sides of the argument. Knowing and understanding why they disagree with you will help you have more informed, educated, and effective conversations in the future.
3- You disobey God by not following His command to "love one another." John 15:12 is clear in its command that we are to love each other. Love does not judge. No one sin is greater than another (although this is a very hard concept to wrap our brains around, at times). We are to hate the sin, but love the sinner, and we are all sinners.
When you have the opportunity to be friends with someone who doesn't believe the same things you do and does not know Christ as their personal Savior, show them His love through you.