Grace is not an abstraction. Grace is Jesus Christ.
Paul’s ‘Christ your life’ is a bridge too far for some Believers because ‘believing’ for them, involves talk of grace followed by the enumeration of a list of things they think Christians must do -  which contradicts what they just said. This list eliminates grace and makes their Christianity something that God never did (make it). It’s surprising how many can talk of grace and busy themselves earning it.
A brother took offence when the preacher observed that there were people in the meeting who did not know God – despite their avid Christianity. We learn to know God through the person of Christ - the Jesus Lens. But if we view Christ through the law, He is not the Christ of God and neither is this His Gospel. The Christ of legalism is a false christ and the fruit of it is a non-life gospel.
There is a sense in which ‘grace can be bought’ – but it is never purchased by us. In a sense our salvation has been bought by Christ but not in way in which he pays off a peeved Father God. God was in Christ reconciling the world to Himself. This is to say that the triune God reached out in Jesus Christ to draw us into companionship with God and undo the estrangement of Adam so that God’s vision for the enjoyment of sons and daughters would be realised.
Nevertheless, we cannot ‘buy’ acceptance with God by having faith. The result of the cross is reconciliation with God for all. The invitation of God is for all who would be alive in God’s life to agree with Christ that He has drawn us into His life.
Martin Davis observes that, “
We must be clear about the place of personal faith in relation to God’s gracious self-giving in Jesus. Contrary to much evangelical teaching, “faith” is not a pre-condition for our reconciliation with the Father.
Rather, “faith” is the conscious, joyful acceptance of our reconciliation with God in Jesus Christ. Faith is “the acknowledgement, recognition, and confession of the reality of reconciliation.”
To be sure, “faith” is not about making a “decision for Christ” in order to be saved; faith is the grateful recognition that Jesus has already made a “decision” for us. Faith is the humble, open-handed reception of the forgiveness and reconciliation that are already ours in Jesus. In short, faith is our personal “yes” to God’s gracious “Yes,” pronounced to all humanity at the cross.” (1)
‘But what does Scripture say? "Get rid of the slave woman and her son, for the slave woman's son will never share in the inheritance with the free woman's son.’ Gal 4.30 NIV.
Many of us would recognise that this is a better kind of faith than the faith we were brought up with. Others might be annoyed that this looks too easy and makes a nothing of the entitlement that they think they have worked up over a life-time that they call ‘their faith’.
The sad thing about those attempting to earn their inheritance is that they never get it. Sons live in grace. Workers make a religion of buying it. The difference between sons of God and workers is that sons and daughters are alive with a flow of spirit and life. Workers remain involved in straining to validate themselves as sons of God.
(1) Davis Ph.D., Rev. Martin M.. A Window into the Heart of God (p. 26). AsiAfrica Ministries, Inc.. Kindle Edition.