Jehovah's Witnesses believe in salvation by means of faith in Jesus Christ, and that we demonstrate that faith by being obedient to Jesus' commands.
I don't think I could describe it any better than the article on jw.org: What Is Salvation?
The article summarizes the cited scriptures, but to fully understand what Jehovah's Witnesses believe, you really need to read those scriptures. If you read the article directly from jw.org, the little dialog boxes make looking up the scriptures much easier.
The Bible’s answer
The terms “save” and “salvation” are sometimes used by Bible writers to convey the idea of a person’s being delivered from danger or destruction. (Exodus 14:13, 14; Acts 27:20) Often, though, these terms refer to deliverance from sin. (Matthew 1:21) Since death is caused by sin, people who are saved from sin have the hope of living forever.—John 3:16, 17.
What is the way to salvation?
To gain salvation, you must exercise faith in Jesus and demonstrate that faith by obeying his commands.—Acts 4:10, 12; Romans 10:9, 10; Hebrews 5:9.
The Bible shows that you must have works, or acts of obedience, to prove that your faith is alive. (James 2:24, 26) However, this does not mean that you can earn salvation. It is “God’s gift” based on his “undeserved kindness,” or “grace.”—Ephesians 2:8, 9; King James Version.
Can you lose out on salvation?
Yes. Just as a person saved from drowning could fall or jump back into the water, a person who has been saved from sin but fails to keep exercising faith could lose out on salvation. For this reason, the Bible urges Christians who have received salvation “to put up a hard fight for the faith.” (Jude 3) It also warns those who have been saved: “Keep working out your own salvation with fear and trembling.”—Philippians 2:12.
Who is the Savior—God or Jesus?
The Bible identifies God as the primary source of salvation, often referring to him as “Savior.” (1 Samuel 10:19; Isaiah 43:11; Titus 2:10; Jude 25) In addition, God used various men to deliver the ancient nation of Israel, and the Bible calls them “saviors.” (Nehemiah 9:27; Judges 3:9, 15; 2 Kings 13:5) Likewise, since God provides salvation from sin through the ransom sacrifice of Jesus Christ, the Bible refers to Jesus as “Savior.”—Acts 5:31; Titus 1:4.
Will everyone be saved?
No, some people will not be saved. (2 Thessalonians 1:9) When Jesus was asked, “Are those being saved few?” he replied: “Exert yourselves vigorously to get in through the narrow door, because many, I tell you, will seek to get in but will not be able.”—Luke 13:23, 24.
Here are some more related questions answered on jw.org: