Two different things get asked under this question, and it's worth separating them.
First: what saves you. Paul's answer to the jailer's own version of this question — "what must I do to be saved?" — is not a program of self-improvement but a person: "Believe in the Lord Jesus Christ, and you will be saved" (Acts 16:31). Romans 10:9 makes the same shape explicit: confess Jesus as Lord, believe God raised him from the dead, "you will be saved." And Ephesians 2:8 rules out the idea that this is your achievement at all — "by grace you have been saved through faith, and that not of yourselves; it is the gift of God." So the ground of assurance is not a feeling or a performance record. It's whether you have actually trusted Christ — not admired him, not agreed he existed, but staked your standing with God on what he did rather than on what you've managed.
Second: whether that trust is real. Paul does tell the Corinthians to check this — "Examine your own selves, whether you are in the faith. Test your own selves" (2 Corinthians 13:5). But note what the test is aimed at: not sinlessness, but whether Christ is actually in you, whether there's been real change. 1 Corinthians 6:11 describes people with genuinely ugly pasts and says of them plainly: "you were washed... sanctified... justified." The change is real but it isn't the ground — it's the evidence.
So the honest order is: trust is not measured by the intensity of your certainty about your own feelings, but is anchored outside yourself, in what Christ did, and then confirmed, not created, by a life that's actually turning toward him. If you're asking because you're not sure you ever really did that first thing — that's a different, answerable question, and worth asking plainly.
brought them out, and said, "Sirs, what must I do to be saved?"closest in meaning to what you asked
Greek Nestle 1904
καὶ προαγαγὼν αὐτοὺς ἔξω ἔφη Κύριοι, τί με δεῖ ποιεῖν ἵνα σωθῶ;
- καὶ καί conjunction G2532
- προαγαγὼν προάγω verb · aorist active participle, nominative singular masculine G4254
- αὐτοὺς αὐτός personal pronoun · accusative plural masculine G846
- ἔξω ἔξω adverb G1854
- ἔφη φημί verb · imperfect active indicative, 3rd person singular G5346
- Κύριοι, κύριος noun · vocative plural masculine G2962
- τί τίς interrogative pronoun · accusative singular neuter G5101
- με ἐγώ personal pronoun G1473
- δεῖ δεῖ verb · present active indicative, 3rd person singular G1163
- ποιεῖν ποιέω verb · present active infinitive G4160
- ἵνα ἵνα conjunction G2443
- σωθῶ; σῴζω verb · aorist passive subjunctive, 1st person singular G4982
Punctuation is editorial — the manuscripts carry none.
See also 5
- Acts 2:37 Now when they heard this, they were cut to the heart, and said to Peter and the rest of the apostles, "Brothers, what shall we do?"
- John 6:27 Don't work for the food which perishes, but for the food which remains to eternal life, which the Son of Man will give to you. For God the Father has sealed him."
- Luke 3:10 The multitudes asked him, "What then must we do?"
- Acts 22:10 I said, 'What shall I do, Lord?' The Lord said to me, 'Arise, and go into Damascus. There you will be told about all things which are appointed for you to do.'
- James 2:13 For judgment is without mercy to him who has shown no mercy. Mercy triumphs over judgment.
Examine your own selves, whether you are in the faith. Test your own selves. Or don't you know about your own selves, that Jesus Christ is in you?—unless indeed you are disqualified.closest in meaning to what you asked
Greek Nestle 1904
Ἑαυτοὺς πειράζετε εἰ ἐστὲ ἐν τῇ πίστει, ἑαυτοὺς δοκιμάζετε· ἢ οὐκ ἐπιγινώσκετε ἑαυτοὺς ὅτι Ἰησοῦς Χριστὸς ἐν ὑμῖν; εἰ μήτι ἀδόκιμοί ἐστε.
- Ἑαυτοὺς ἑαυτοῦ reflexive pronoun G1438
- πειράζετε πειράζω verb · present active imperative, 2nd person plural G3985
- εἰ εἰ conditional G1487
- ἐστὲ εἰμί verb · present active indicative, 2nd person plural G1510
- ἐν ἐν preposition G1722
- τῇ ὁ article · dative singular feminine G3588
- πίστει, πίστις noun · dative singular feminine G4102
- ἑαυτοὺς ἑαυτοῦ reflexive pronoun G1438
- δοκιμάζετε· δοκιμάζω verb · present active imperative, 2nd person plural G1381
- ἢ ἤ particle G2228
- οὐκ οὐ particle · nominative G3756
- ἐπιγινώσκετε ἐπιγινώσκω verb · present active indicative, 2nd person plural G1921
Punctuation is editorial — the manuscripts carry none.
See also 5
- Lamentations 3:40 Let us search and try our ways, and turn again to Yahweh.
- 1 Corinthians 11:28 But let a man examine himself, and so let him eat of the bread and drink of the cup.
- Psalm 139:23 Search me, God, and know my heart. Try me, and know my thoughts.
- 1 Corinthians 9:27 but I beat my body and bring it into submission, lest by any means, after I have preached to others, I myself should be disqualified.
- Revelation 2:5 Remember therefore from where you have fallen, and repent and do the first works; or else I am coming to you swiftly, and will move your lamp stand out of its place, unless you repent.
Some of you were such, but you were washed. You were sanctified. You were justified in the name of the Lord Jesus, and in the Spirit of our God.closest in meaning to what you asked
Greek Nestle 1904
καὶ ταῦτά τινες ἦτε· ἀλλὰ ἀπελούσασθε, ἀλλὰ ἡγιάσθητε, ἀλλὰ ἐδικαιώθητε ἐν τῷ ὀνόματι τοῦ Κυρίου Ἰησοῦ Χριστοῦ καὶ ἐν τῷ Πνεύματι τοῦ Θεοῦ ἡμῶν.
- καὶ καί conjunction G2532
- ταῦτά οὗτος demonstrative pronoun · nominative plural neuter G3778
- τινες τὶς indefinite pronoun · nominative plural masculine G5100
- ἦτε· εἰμί verb · imperfect active indicative, 2nd person plural G1510
- ἀλλὰ ἀλλά conjunction G235
- ἀπελούσασθε, ἀπολούω verb · aorist middle indicative, 2nd person plural G628
- ἀλλὰ ἀλλά conjunction G235
- ἡγιάσθητε, ἁγιάζω verb · aorist passive indicative, 2nd person plural G37
- ἀλλὰ ἀλλά conjunction G235
- ἐδικαιώθητε δικαιόω verb · aorist passive indicative, 2nd person plural G1344
- ἐν ἐν preposition G1722
- τῷ ὁ article · dative singular neuter G3588
Punctuation is editorial — the manuscripts carry none.
See also 5
- 1 Corinthians 1:30 Because of him, you are in Christ Jesus, who was made to us wisdom from God, and righteousness and sanctification, and redemption,
- Colossians 3:5 Put to death therefore your members which are on the earth: sexual immorality, uncleanness, depraved passion, evil desire, and covetousness, which is idolatry.
- Romans 6:17 But thanks be to God that, whereas you were bondservants of sin, you became obedient from the heart to that form of teaching to which you were delivered.
- 1 Corinthians 1:2 to the assembly of God which is at Corinth—those who are sanctified in Christ Jesus, called saints, with all who call on the name of our Lord Jesus Christ in every place, both theirs and ours:
- Acts 22:16 Now why do you wait? Arise, be baptized, and wash away your sins, calling on the name of the Lord.'
that if you will confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved.closest in meaning to what you asked
Greek Nestle 1904
ὅτι ἐὰν ὁμολογήσῃς ἐν τῷ στόματί σου Κύριον Ἰησοῦν, καὶ πιστεύσῃς ἐν τῇ καρδίᾳ σου ὅτι ὁ Θεὸς αὐτὸν ἤγειρεν ἐκ νεκρῶν, σωθήσῃ·
- ὅτι ὅτι conjunction G3754
- ἐὰν ἐάν conditional G1437
- ὁμολογήσῃς ὁμολογέω verb · aorist active subjunctive, 2nd person singular G3670
- ἐν ἐν preposition G1722
- τῷ ὁ article · dative singular neuter G3588
- στόματί στόμα noun · dative singular neuter G4750
- σου σύ personal pronoun G4771
- Κύριον κύριος noun · accusative singular masculine G2962
- Ἰησοῦν, Ἰησοῦς noun · accusative singular masculine G2424
- καὶ καί conjunction G2532
- πιστεύσῃς πιστεύω verb · aorist active subjunctive, 2nd person singular G4100
- ἐν ἐν preposition G1722
Punctuation is editorial — the manuscripts carry none.
See also 5
- Luke 12:8 "I tell you, everyone who confesses me before men, the Son of Man will also confess before the angels of God;
- Acts 16:31 They said, "Believe in the Lord Jesus Christ, and you will be saved, you and your household."
- Philippians 2:11 and that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father.
- Matthew 10:32 Everyone therefore who confesses me before men, I will also confess him before my Father who is in heaven.
- 1 John 4:2 By this you know the Spirit of God: every spirit who confesses that Jesus Christ has come in the flesh is of God,
receiving the result of your faith, the salvation of your souls.closest in meaning to what you asked
Greek Nestle 1904
κομιζόμενοι τὸ τέλος τῆς πίστεως σωτηρίαν ψυχῶν.
- κομιζόμενοι κομίζω verb · present middle or passive participle, nominative plural masculine G2865
- τὸ ὁ article · accusative singular neuter G3588
- τέλος τέλος noun · accusative singular neuter G5056
- τῆς ὁ article · genitive singular feminine G3588
- πίστεως πίστις noun · genitive singular feminine G4102
- σωτηρίαν σωτηρία noun · accusative singular feminine G4991
- ψυχῶν. ψυχή noun · genitive plural feminine G5590
Punctuation is editorial — the manuscripts carry none.
See also 3
- Romans 6:22 But now, being made free from sin and having become servants of God, you have your fruit of sanctification and the result of eternal life.
- James 1:21 Therefore, putting away all filthiness and overflowing of wickedness, receive with humility the implanted word, which is able to save your souls.
- Hebrews 11:13 These all died in faith, not having received the promises, but having seen them and embraced them from afar, and having confessed that they were strangers and pilgrims on the earth.
for by grace you have been saved through faith, and that not of yourselves; it is the gift of God,closest in meaning to what you asked
Greek Nestle 1904
τῇ γὰρ χάριτί ἐστε σεσῳσμένοι διὰ πίστεως· καὶ τοῦτο οὐκ ἐξ ὑμῶν, Θεοῦ τὸ δῶρον·
- τῇ ὁ article · dative singular feminine G3588
- γὰρ γάρ conjunction G1063
- χάριτί χάρις noun · dative singular feminine G5485
- ἐστε εἰμί verb · present active indicative, 2nd person plural G1510
- σεσῳσμένοι σῴζω verb · perfect passive participle, nominative plural masculine G4982
- διὰ διά preposition G1223
- πίστεως· πίστις noun · genitive singular feminine G4102
- καὶ καί conjunction G2532
- τοῦτο οὗτος demonstrative pronoun · nominative singular neuter G3778
- οὐκ οὐ particle · nominative G3756
- ἐξ ἐκ preposition G1537
- ὑμῶν, σύ personal pronoun G4771
Punctuation is editorial — the manuscripts carry none.
See also 5
- Romans 3:22 even the righteousness of God through faith in Jesus Christ to all and on all those who believe. For there is no distinction,
- Ephesians 2:5 even when we were dead through our trespasses, made us alive together with Christ—by grace you have been saved—
- Romans 4:16 For this cause it is of faith, that it may be according to grace, to the end that the promise may be sure to all the offspring, not to that only which is of the law, but to that also which is of the faith of Abraham, who is the father of us all.
- John 1:12 But as many as received him, to them he gave the right to become God's children, to those who believe in his name:
- Romans 10:17 So faith comes by hearing, and hearing by the word of God.
They said, "Believe in the Lord Jesus Christ, and you will be saved, you and your household."brought in by cross-reference
Greek Nestle 1904
οἱ δὲ εἶπαν Πίστευσον ἐπὶ τὸν Κύριον Ἰησοῦν, καὶ σωθήσῃ σὺ καὶ ὁ οἶκός σου.
- οἱ ὁ article · nominative plural masculine G3588
- δὲ δέ conjunction G1161
- εἶπαν λέγω verb · aorist active indicative, 3rd person plural G3004
- Πίστευσον πιστεύω verb · aorist active imperative, 2nd person singular G4100
- ἐπὶ ἐπί preposition G1909
- τὸν ὁ article · accusative singular masculine G3588
- Κύριον κύριος noun · accusative singular masculine G2962
- Ἰησοῦν, Ἰησοῦς noun · accusative singular masculine G2424
- καὶ καί conjunction G2532
- σωθήσῃ σῴζω verb · future passive indicative, 2nd person singular G4982
- σὺ σύ personal pronoun G4771
- καὶ καί conjunction G2532
Punctuation is editorial — the manuscripts carry none.
See also 5
- John 1:12 But as many as received him, to them he gave the right to become God's children, to those who believe in his name:
- John 3:36 One who believes in the Son has eternal life, but one who disobeys the Son won't see life, but the wrath of God remains on him."
- Acts 2:38 Peter said to them, "Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of sins, and you will receive the gift of the Holy Spirit.
- Romans 10:9 that if you will confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved.
- Acts 11:13 He told us how he had seen the angel standing in his house and saying to him, 'Send to Joppa and get Simon, who is called Peter,
From the interpretive tradition
The essence of sin is man substituting himself for God, while the essence of salvation is God substituting himself for man.
That which He has not assumed He has not healed; but that which is united to His Godhead is also saved.
A worked example. Ask your own and it starts a new thread.