"A man that hath friends must shew himself friendly: and there is a friend that sticketh closer than a brother." Proverbs 18:24
To have a friend is an essential need for everyone. Ideally, one's spouse would be one's friend and then lover, in that order. Again ideally, one's parent should be one's friend. What is a friend? A definition I learned many years ago is: "A friend is one who knows you as you are, understands where you have been, accepts who you have become, and still invites you to grow." (What a Friend we have in Jesus!)
Friendliness is different. A definition for friendliness might be: "A friendly person is one who somewhat knows you as you are, sometimes understands where you have been, once in a while accepts who you've become, rarely invites you to grow, and will not be there when you need him/her the most." Friendliness develops acquaintances, commonly called friends, and acquaintances are a casual type of relationship. A friend, as used in Proverbs 18:24b, is a deep relationship, that is, one where a person can openly share their heart with their friend without fear of judgment or condemnation coming from that friend. Friendly people will often judge and condemn when there is an attempt to deepen the casual relationship, that is, when one tries to share a little bit of their heart with a "friendly" person. Remember, "friendly" means "like a friend." It does not mean "to be a friend."
Jesus is said to be a Friend of sinners. Since we are all sinners, He is a Friend to all even though most do not accept Him. If we are to be like Christ, then we need to be a friend-not friendly-to all. This can only be accomplished by focusing on Christ, following His direction and guidance, and letting Him work through us.
What will you choose: to be a friend or just friendly?