Ephesians 1:6-10

to the praise of his glorious grace, with which he has blessed us in the Beloved. In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace,

(v6-7, ESV)

This is because of his grace. We are saved by grace through faith in Jesus Christ. Because of his grace we have redemption and forgiveness. It's not just a little bit of forgiveness and redemption either.

Then Peter came to Jesus and asked, "Lord, how many times shall I forgive my brother when he sins against me? Up to seven times?"

Jesus answered, "I tell you, not seven times, but seventy-seven times.

(Matthew 18:21-22, NIV)

Peter was asking how many times he needed to forgive someone. Basically, we aren't supposed to keep track of how many times we forgive someone. In the same way, God's forgiveness and redemption is not limited to a number. The power of his forgiveness is not limited to only certain sins. Now, some may argue that those who blaspheme the Holy Spirit will not be forgiven (Mark 3:29, Luke 12:10). I'm not going to deal with this now, but this exception (if it is in fact an exception) does not change the riches of God's grace. It is by the riches of his grace that we are redeemed and forgiven.

which he lavished upon us, in all wisdom and insight, making known to us the mystery of his will, according to his purpose, which he set forth in Christ as a plan for the fullness of time, to unite all things to him, things in heaven and things on earth.

(v8-10, ESV)

This mystery is that the Gentiles are fellow heirs, members of the same body and partakers of the promise in Christ Jesus through the gospel.

(Ephesians 3:6, ESV)

Paul tells us what this mystery is in chapter 3. The Jews were God's people and always have been God's people. They took pride in the fact that God chose them. However, contrary to their understanding, God made a way for them to be saved.

God made the mystery known to us. This mystery wasn't something that was thought up the last minute. God planned this just as he predestined us to be holy and blameless in his sight. This was all part of his plan before the foundation of the world. This plan as we know was carried out by Jesus. His death on the cross made a way for the Gentiles to be redeemed to God. As a result, both Jews and Gentiles have a way to be redeemed and forgiven. All can be saved as God planned it before the creation of the world.