Acts 16 provides one example of the many adventures and challenges faced by the early Christian church. It recounts the preaching of Paul and Silas, their persecution, and their imprisonment. Rather than feeling discouraged, while in jail the two Christians prayed and sang hymns. An earthquake shook the prison, the doors opened, and the chains of all the prisoners were loosed. The jailer, greatly concerned, approached the two, falling before them and pleading, "Sirs, what must I do to be saved?" Paul and Silas replied, "Believe in the Lord Jesus, and you will be saved …" (Acts 16:30-31, NIV).
The passage is important in relation to the topic of salvation or, technically, soteriology. In everyday language, salvation has to do with how we are saved or delivered from our fallen condition. We are, as noted in another article in this series, rebels in God's image, fallen and in need of restoration. In Christian terms salvation refers to this restoration - setting right what is wrong.
What Salvation is Not
Before clarifying salvation in biblical terms, it will be helpful to look at ways of "salvation" that are not in line with Christian theology. Probably the most common approach is works-based. As the name suggests, this approach to salvation relies on human works and what we can do in order to save ourselves. But when it comes to salvation Christianity is Savior-centered, not self-centered: "For it is by grace you have been saved, through faith - and this not from yourselves, it is the gift of God - not by works, so that no one can boast" (Ephesians 2:8-9 NIV). Good works are the natural outcome of following salvation through Christ.
Neither is salvation universal, meaning that not everyone will be saved. This does not mean that God does not love everyone. Indeed, He "wants all men to be saved and to come to a knowledge of the truth" (1 Timothy 2:4 NIV). But only Christ is "the way and the truth and the life" (John 14:6 NIV).
Salvation is not found in legalism, either. Strict adherence to a list of do's and don'ts is not what Christian salvation is about. Romans 3:20 reads, "no one will be declared righteous in his [God's] sight by observing the law; rather, through the law we become conscious of sin." We all "fall short of the glory of God" (Romans 3:23 NIV).
Some beliefs claim that salvation in a biblical sense is not required. Instead, terms such as "spiritual liberation" or "enlightenment" are used. Most of the time this is found in variations of Eastern worldviews such as pantheism. Usually the core idea is that human beings need only realize that they are perfect and divine, resulting in "salvation." But we are far from perfect and deep down everyone knows this fact. God exists, but He is not us and we are not Him.
What then is biblical salvation? It's not by works, legalism enlightenment, and it's not universal. What, then, must we do to be saved? It's important to keep in mind that salvation encompasses what God has done for us, not what we can do for Him. God has taken the initiative in His plan of redemption, reaching out to us through Christ. Hence, the answer regarding the question of salvation as given by Paul and Silas is, "Believe in the Lord Jesus …" (Acts 16:31 NIV). The Greek word translated "believe" in the passage is pisteuo, meaning "to believe, put one's faith in, trust, with an implication that actions based on that trust may follow." Belief, then, encompasses more than just knowing about Jesus. One must also act on this knowledge, combining faith and trust and acting on it.
Salvation also entails repentance - a sincere willingness to radically change our behavior (see, for instance Matthew 3:2; 4:17; Mark 6:12; Luke 13:3-5; Acts 2:38). There is a certain degree of humility that is also required on our part in order to submit to Christ and receive salvation. In the story of the jailer, for instance, we are told he "fell trembling before Paul and Silas" (Acts 16:29 NIV). He also addressed them as "Sirs," using a term of respect and acknowledging the authority of Paul and Silas in Christ. In other words, the roles are reversed. Rather than the Christian prisoners being under the authority of the jailer, it is the jailer who now humbly submits to them, sincerely seeking God's salvation.
Salvation: Simple But Deep
The Christian message of salvation is simple enough for everyone to understand, but deep enough to entail a lifetime of study. Salvation is very much interconnected to other aspects of theology such as the meaning of Christ's Atonement, the human condition, God's attributes such as His justice and holiness, our eternal destiny and more. "Jesus is Lord" is a simple statement of faith, but in relation to salvation it's important to know who Jesus is, who He claimed to be and what it means to believe and follow Him.
The Apostle Paul summarized the message of salvation - the Gospel - in 1 Corinthians 15, where he wrote, under divine inspiration: "Now, brothers, I want to remind you of the gospel I preached to you, which you received and on which you have taken your stand. By this gospel you are saved, if you hold firmly to the word I preached to you. Otherwise, you have believed in vain. For what I received I passed on to you as of first importance: that Christ died for our sins according to the Scriptures, that he was buried, that he was raised on the third day according to the Scriptures, and that he appeared to Peter, and then to the Twelve" (1 Corinthians 15:1-5 NIV).
In this passage Paul stresses the literal death and resurrection of Christ, "for our sins," the biblical foundations for this (acknowledging the authority of the Bible), and the proof provided by Christ's many post-resurrection appearances.
Christ: The Center of Salvation
But we are not expected to "just believe" and be saved, without any appeal to proof or reason. Certainly faith plays a part in salvation, but there is a difference between blind faith and justified faith. Even Acts 1:3, for instance, observes of Christ, "After his suffering, he showed himself to these men and gave many convincing proofs that he was alive," while in Acts 26:25, Paul states that his Christian beliefs are "true and reasonable."
When Paul and Silas said to the jailer, "Believe in the Lord Jesus, and you will be saved …" (Acts 16:31 NIV), they understand the centrality of Christ in salvation. The word translated as "saved" is charged with deep theological implications, meaning "to save, rescue, deliver; to heal … to be in right relationship with God, with the implication that the condition before salvation was one of grave danger or distress" 
Christ's death and resurrection offers every one of us an opportunity for salvation. When is the right time to accept His offer? As C.S. Lewis said, "Now, today, this moment, is our chance to choose the right side. God is holding back to give us that chance. It will not last forever. We must take it or leave it."
 See, "Human Beings: Rebels in God's Image?"
 NIV Exhaustive Concordance (Zondervan, 1999), electronic edition.
 C.S. Lewis, Mere Christianity (Macmillan, 1952), Book II, chapter 6, p. 66.