Salvation is being delivered from the righteous judgment of God that will fall upon those who have sinned by breaking his law. In order to be saved from that judgment, we must trust Christ. We must receive what he has done on the cross on our behalf as a substitute for us, who removes our sin (Heb. 9:26; 1 Pet. 2:24) and gives us righteousness (Phil. 3:9). This can only be done by faith because our righteous deeds are filthy rags before God (Isaiah 64:6).
There are different groups that teach that salvation is attained by doing good works and trusting in Christ, such as Roman Catholicism, Mormonism, Jehovah's Witnesses, etc. But this cannot be so. Sure, we want people to do good works, but it is not the good works that contribute to salvation. Let's take a look at two sections of Scripture where Jesus teaches on this topic, Matt. 7:22-23 and Luke 18:9-14.
Matt. 7:22-23, "Many will say to Me on that day, "Lord, Lord, did we not prophesy in Your name, and in Your name cast out demons, and in Your name perform many miracles?" 23 And then I will declare to them, "I never knew you; depart from Me, you who practice lawlessness."
You can see that on the day of judgment there will be people who believe in God and will appeal for their salvation based on their faith in him (they call him Lord) and their good deeds, i.e., prophesying, casting out demons, and performing miracles. Yet Jesus condemns them. Why? It is because they are appealing to their faith and works.
Luke 18:9:14, "And He also told this parable to certain ones who trusted in themselves that they were righteous, and viewed others with contempt: 10 “Two men went up into the temple to pray, one a Pharisee, and the other a tax-gatherer. 11 The Pharisee stood and was praying thus to himself, ‘God, I thank Thee that I am not like other people: swindlers, unjust, adulterers, or even like this tax-gatherer. 12 ‘I fast twice a week; I pay tithes of all that I get.’ 13 But the tax-gatherer, standing some distance away, was even unwilling to lift up his eyes to heaven, but was beating his breast, saying, ‘God, be merciful to me, the sinner!’ 14 I tell you, this man went down to his house justified rather than the other; for everyone who exalts himself shall be humbled, but he who humbles himself shall be exalted.
In these verses, Jesus talks about a Pharisee who believed in God, did good things, and did not do bad things. Yet, he was not saved. On the other hand, the tax gatherer (verse 13) did not appeal to works, but only asked for God's mercy. Jesus says that he was justified, not the Pharisee. That means he was legally righteous in God's eyes. Notice, Jesus taught justification by faith alone. Let's take a look at two things that Paul the Apostle said...
- Rom. 3:28, "For we maintain that a man is justified by faith apart from works of the Law."
- Rom. 4:1-5, "What then shall we say that Abraham, our forefather according to the flesh, has found? 2 For if Abraham was justified by works, he has something to boast about; but not before God. 3 For what does the Scripture say? “And Abraham believed God, and it was reckoned to him as righteousness.” 4 Now to the one who works, his wage is not reckoned as a favor, but as what is due. 5 But to the one who does not work, but believes in Him who justifies the ungodly, his faith is reckoned as righteousness.
In the 1st verse, Romans 3:28, we see the justification is apart from the works of the Law. Now, the works of the Law are summed up by Jesus when he says...
Matt. 22:37-40, "You shall love the Lord your God with all your heart, and with all your soul, and with all your mind. 38 This is the great and foremost commandment. 39 The second is like it, You shall love your neighbor as yourself. 40 On these two commandments depend the whole Law and the Prophets."
When Jesus said that you are to love God, he was quoting Deuteronomy 6:5. When he was talking about loving your neighbor, he was quoting Leviticus 19:18. In other words, Jesus was quoting the Old Testament law and said that these two commandments summarize the whole Law. So when we see that Paul the apostle says in Romans 3:28 the person is justified by faith apart from the works of the Law, this must necessarily include any and all Old Testament laws. That means it is salvation by faith alone, not by any good works and faith.
In addition, when we look at Romans 4:1-5 above we see that Paul the apostle is talking about justification before God (verse 2). He says that Abraham believed God and his belief was reckoned as righteousness (verse 3). In verse 5 he says that the one who does not work but believes, his faith is reckoned as righteousness. If we only have faith and works as options, and works are removed, then faith is alone; hence, salvation by faith alone. This is why we say that the Bible teaches justification by faith alone in Christ alone. It cannot be that we are saved by works, and it cannot be that were saved by faith and works. It is by faith alone.