Christianity is antithetical to racism.
Every person, no matter their race, is made in the image of God. God’s blessing through Abraham is to all peoples (Gen 12:3). The blessing has been realized through Christ, who sacrificed and died for all of us.
Christ accepted all sorts of people—prostitutes, lepers, disabled, tax collectors, and Samaritans.
The Israelites hated the Samaritans, but Christ befriended them. John 4:4 described Christ insisted on going through Samaria, though there were other paths. That trip depicted Christ having the longest conversation recorded in the Bible, and it was with a Samaritan woman. Later, He stayed with the Samaritans for two days (John 4:40). Other examples include Christ healing a Samaritan leper, and one of His most memorable parables featured a good Samaritan (Luke 17:11-19, Luke 10:25-37). Such behaviors irked the Jews to no end, causing some to even consider Him a Samaritan (John 8:48).
The early church did not separate Jews from Gentiles, or the uneducated (e.g., the Scythian) from the educated (Galatians 3:28, Colossians 3:11).
As to genetic differences based on skin color, they are in the 0.01 percent range. Genetic variations within a race are much higher than variations among different races.
In the US, slaves were initially Scots, Irishman, Englishmen, and others. Later, kidnapping people from Africa as slaves became a big business. One reason was because African slaves were much easier to track down if they ran away. Once here, they were isolated, oppressed, denied equal rights, and stripped of numerous opportunities.
Those who would discriminate based on skin color are driven by power and greed. It is a way to justify suppression and exploitation.
Christ tears down walls and facilitate reconciliation (2 Corinthians 5:16-19).
Christ humbled Himself to become human and die for us (Philippians 2:5-8). He used His privilege for us.
Paul followed Christ and gave up his privilege as a Roman to spread the gospel to Gentiles.
We also should follow Christ and use our privilege to help those in need.
Fight racism with love. Instead of suppressing those different from us, include them and help them if they need it. Racism is a spiritual battle. Ask God to strengthen us to win it.
Summarized from a John Ortberg sermon
各族人民都是按照上帝的形象被造。 上帝通过亚伯拉罕赐福所有人 （创世纪12：3）。 这赐福已经通过基督得以实现。 祂献上自己为祭，为每一个人死在十字架上。
基督接纳各种各样的人 - 妓女，麻风病人，残疾人，税吏和撒玛利亚人。
以色列人厌恶撒玛利亚人，但基督却与他们为友。 约翰福音4：4描述虽然还有其它途径可行，基督仍然坚持经过撒玛利亚。在那次旅程中祂与一个撒玛利亚妇人进行了圣经记载中最长的对话。后来，祂甚至在撒玛利亚住了两天 （约翰福音4:40）。其它例子包括医治撒玛利亚的麻风病人和给律法师讲解撒玛利亚人的比喻，后者是基督最令人难忘的比喻之一 （路加福音17：11-19; 10：25-37）。 这些行为大大地激怒当时的犹太人，以至有些人甚至把祂当作撒玛利亚人看待 （约翰福音8:48）。
基督谦卑自己，成为与我们一样的人，为我们受死 （腓立比书2：5-8）。 祂使用祂的特权来拯救我们。