The death of Christ was an eminent part of God's overall plan to bring many sons to glory. In order for us to be made acceptable in God our sins had to be atoned for.
Hebrews 2:10-11 For it was fitting for Him, for whom are all things and by whom are all things, in bringing many sons to glory, to make the author of their salvation perfect through sufferings. For both He who sanctifies and those who are being sanctified are all of one, for which reason He is not ashamed to call them brethren
When God's call of salvation goes out to people, it knows no boundaries. It goes out to all peoples of all races, cultures, backgrounds, genders, personalities, classes, political backgrounds, etc. God's idea is to create one new man out of all these diversities of people. This is where the fun begins and where the work of the cross comes into play.
God has given to each person in the body a measure of faith and gifting in Him, but for the body to come together as the glorious body of Christ that He has destined it to, there must be a meshing together.