Ephesians 3:6
“to be specific, that the Gentiles are fellow heirs and fellow members of the body, and fellow partakers of the promise in Christ Jesus through the gospel.”
In this passage the mystery is described is the Gentiles being fellow heirs of the body and fellow partakers of the promise. This was always meant to be. However, Israel was the focus in the Old Testament. It was as if God's blessings were channeled through the Jews until Jesus came. He is the shower head which broadens spray of blessings to include everyone.
The Jews had a problem with that. The Old Testament instructed them to be insular as to the purity of their race and faith. However, there were hints of inclusion here and there. So, one knowledgable in the law would have understood that God's blessings would have included the gentiles.
It's God's way to branch out to broaden our circle. We can't be comfortable to the point that we don't welcome others. It can be uncomfortable. However, God's way is to sacrifice our comfort to be open to others.
This is what Jesus meant in Matthew 16:24, "Then Jesus told His disciples, “If anyone wants to come after Me, he must deny himself and take up his cross and follow Me". We look back knowing that Jesus experienced the cross and we understand the great lengths He went to for us. However, I wonder if those who originally heard that thought it was an odd comparison. The cross was for criminals and zealots. He underwent capitol punishment for us. Common citizens wouldn't see the electric chair as anything that applied to them. To take up one's cross is to execute self desire for the sake of others. It takes God's love to do this.
In the Garden of Gethsemane, Jesus asked if the cross could be avoided. He understood the enormous pain that awaited Him. Yet, He submitted to the plan to go forward for us. Thus making the mystery of God's salvation going to the gentiles possible.
To personalize it, because of God's plan and Jesus' sacrifice I'm a child of God and a citizen of His kingdom. I have joy in my heart, a promise that all things will work out for the good, a past that God has blessed, family and friends that are blessed and a knowledge that He uses His children to be instruments of blessing that lead others to Him. Wow! Simply amazing.
His desire is for all to be in His family. It's like all are pre-children. He works in all hearts to lead them to Him. Unfortunately the devil spreads his lies keeping many away. Selfishness and sin also keep them away. Thank You God that You never stop working.
Lord, thank You for this mystery. You are a tireless worker in seeking all to come. Thank You, God.