The Bethel Music song The Blood highlights the idea of “sola fide” – the Reformation concept, in Latin, of salvation by faith alone. The lyrics read:

It’s never been about performance
Perfection striving for acceptance
Let me tell you
It’s only by the blood
It’s never been about deserving or earning
It’s a gift that’s freely given
Let me tell you
It’s only by the blood

Paul makes the same sort of point in Romans 4:4-8 (NLT). He writes:

When people work, their wages are not a gift, but something they have earned. But people are counted as righteous, not because of their work, but because of their faith in God who forgives sinners. David also spoke of this when he described the happiness of those who are declared righteous without working for it:

“Oh, what joy for those
whose disobedience is forgiven,
whose sins are put out of sight.
Yes, what joy for those
whose record the Lord has cleared of sin.”

Paul continues to make the point in that chapter that Abraham was saved not because of works in the form of circumcision but because of his faith. Paul writers that his salvation was “based not on his obedience to God’s law, but on a right relationship with God that comes by faith”.

So what N.T. Wright calls the “works through which the Jew is defined over against the pagan”, meaning acts like circumcision and Levitical sacrifices, are not what saves. They are merely symbolic. In the same way, in Christianity, baptism of a dying infant in no way affects their salvation.

Likewise, the idea of “works righteousness” – that though striving very hard to be virtuous – we can gain salvation is false. Christians are called to be Christ-like. Faith without works is dead, after all. But it isn’t those works that save. Only by the blood are we saved – i.e. the act of grace on the cross.

This thinking, from Romans 4 and elsewhere, is reflected in the Thirty-Nine Articles of Religion, which say:

We are accounted righteous before God, only for the merit of our Lord and Saviour Jesus Christ by faith, and not for our own works or deservings. Wherefore that we are justified by faith only is a most wholesome doctrine, and very full of comfort…

Paul’s quotation of David comes from Psalm 32, where the king of Israel and Judah continues:

Finally, I confessed all my sins to you
and stopped trying to hide my guilt.
I said to myself, “I will confess my rebellion to the Lord.”
And you forgave me! All my guilt is gone.

Salvation is by faith alone, so how is repentance a thing as well? Well, it’s because they are intertwined. As the website GotQuestions puts it: “Repentance and faith can be understood as two sides of the same coin”.

It adds: “Biblical repentance, in relation to salvation, is changing your mind from rejection of Christ to faith in Christ.”

John Miley, the 19th century theologian, explains:

While faith is the one and only condition of justification, yet a true repentance is always presupposed, because only in such a mental state can the proper faith be exercised. An impenitent soul cannot properly trust in Christ for the forgiveness of sin. In such a state there can be no real sense of its need, and therefore no possibility of the act of trust.

So repentance is the flipside of faith, and the transforming effect of faith will deliver real change in how we act, but it’s faith that we’re saved – our righteousness paid for by Jesus’s blood.