"And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together." (Romans 8: 17)
Today, we are no longer in Adam, but because of God's Son, we are in Christ (Romans 5: 15-19)
As sons of the Living God (1 John 3: 1-3), we have a great inheritance.
"In whom also we have obtained an inheritance, being predestinated according to the purpose of him who worketh all things after the counsel of his own will:" (Ephesians 1:11)
"Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust." (2 Peter 1: 4)
We are not inheritors based on what we do.
The rich man who confronted Jesus had to learn this lesson the hard way:
"And a certain ruler asked him, saying, Good Master, what shall I do to inherit eternal life?" (Luke 18: 18)
The fact is that none of us can do anything to inherit anything. Inheritance is based on adoption, not effort:
"For ye have not received the spirit of bondage again to fear; but ye have received the Spirit of adoption, whereby we cry, Abba, Father." (Romans 8: 15)
This sonship is based on justification by faith, not by law:
"Therefore being justified by faith, we have peace with God through our Lord Jesus Christ:" (Romans 5: 1)
"Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified." (Galatians 2: 16)
We became heirs of God when we believed on Jesus Christ, that through Him we are justified from all things (Acts 13: 38-39)