“And being made perfect, he became the author of eternal salvation unto all them that obey him;” Hebrews 5:9
Some might use this verse to say that our eternal salvation is based upon our works. That if we do not obey the Lord Jesus Christ in everything we do, we cannot have eternal life. However, the command we must obey for salvation is the command to “believe on the Lord Jesus Christ” as in 1 John 3:23:
“And this is his commandment, That we should believe on the name of his Son Jesus Christ, and love one another, as he gave us commandment.” 1 John 3:23
This also involves repentance, as commanded by the apostle Paul:
“And the times of this ignorance God winked at (overlooked); but now commandeth all men every where to repent:” Acts 17:30-31
Repentance is not a work, but looking to God to work on your behalf.
And Jesus answering said unto them, They that are whole need not a physician; but they that are sick. I came not to call the righteous, but sinners to repentance. Luke 5:31
The Gospel is something you obey.
“In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ:” 2 Thessalonians 1:8
“Unto you therefore which believe he is precious: but unto them which be disobedient, the stone which the builders disallowed, the same is made the head of the corner, And a stone of stumbling, and a rock of offence, even to them which stumble at the word, being disobedient: whereunto also they were appointed.” 1 Peter 2:6-8
Notice in this verse that being disobedient here is used in the context of not believing.
“For the time is come that judgment must begin at the house of God: and if it first begin at us, what shall the end be of them that obey not the gospel of God?” 1 Peter 4:17
“But they have not all obeyed the gospel. For Esaias saith, Lord, who hath believed our report?” Romans 10:16
“By whom we have received grace and apostleship, for obedience to the faith among all nations, for his name:” Romans 1:5
“Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began, But now is made manifest, and by the scriptures of the prophets, according to the commandment of the everlasting God, made known to all nations for the obedience of faith:” Romans 16:25-26
In conclusion, the only act of obedience (or the only work) required for salvation is to believe on the Lord Jesus Christ:
“For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast.” Ephesians 2:8-9