Salvation according to the Bible
Believe upon Jesus
Believing upon Jesus (the right Jesus) is a necessity to being saved: John 3:18, "He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God."
We must repent
We must turn from our wicked ways: Luke 5:32, "I came not to call the righteous, but sinners to repentance." and also Luke 13:3, "I tell you, Nay: but, except ye repent, ye shall all likewise perish."
Be born again
We must be born again: John 3:3, "Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God."
If you continue reading in John chapter 3 verses 14 through 21 tells you how you can become born again. Verse 16 pretty much tells you what you need to do: John 3:16, "For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life."
Beware of the 'wrong Jesus'
Warning against 'another Jesus': 2 Corinthians 11:4, "For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him."
The true Jesus would be born of a virgin: Isaiah 7:14, "Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel." (Also see Matthew 1:23) Mormonism for example, believes that the Father (which in their belief is Adam who became a god) came down physically and mated with his 'spirit daughter' Mary and out came Jesus' body. Their Jesus resulted from INCEST and NOT from a virgin birth! They also believe that Satan and Jesus are brothers! That is a mockery to the true Jesus!
Jesus (the right Jesus) is the ONLY way to heaven: John 10:1, 9, "Verily, verily, I say unto you, He that entereth not by the door into the sheepfold, but climbeth up some other way, the same is a thief and a robber... I am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture." John 14:6, "Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me."
Beware of religions that appear to be good
Warning about Satan's ministers appearing to be righteous: 2 Corinthians 11:14, 15, "And no marvel; for Satan himself is transformed into an angel of light. Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works."
Beware of angels giving revelations contrary to God's Word: Another thing I'd like to point out is that the Mormon's "revelation" came from an angel (a fallen angel by the name of Moroni), and in Galatians 1:8 it directly warns us against an angel giving us a revelation that doesn't line up with God's Word, "But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed."
In the end days, there will be many who fall into deceiving religions: 1 Timothy 4:1, "Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils." If you look up seducing in the Greek for that verse, it means deceiving. Deceiving means to appear to be true, yet it's false, or to give a false impression. This verse is talking about religions that appear to be right, but don't lead a person down the path to heaven. For example, Mormonism is the kind of religion they are talking about here, because it 'seems right' and yet it is so far off the track. I think it's pretty clear that Satanism won't lead a person to heaven, but yet it doesn't look like a godly religion either. It's pretty clear that they aren't trying to 'appear' godly. Satan works in different ways in different religions. The goal of Satanism isn't to try to deceive Christians to convert, but to directly bring Satan glory (demon worship, marrying Satan, etc.). Whereas the goal of Mormonism is to appeal to lukewarm Christians and people who are looking for a "nice" religion.
Simply believing in Jesus isn't enough
Just acknowledging Jesus isn't enough: Shortly after John 3:16, it tells us in verse 21, "But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God." Also, James 2:19-26 says, "Thou believest that there is one God; thou doest well: the devils also believe, and tremble. But wilt thou know, O vain man, that faith without works is dead? Was not Abraham our father justified by works, when he had offered Isaac his son upon the altar? Seest thou how faith wrought with his works, and by works was faith made perfect? And the scripture was fulfilled which saith, Abraham believed God, and it was imputed unto him for righteousness: and he was called the Friend of God. Ye see then how that by works a man is justified, and not by faith only. Likewise also was not Rahab the harlot justified by works, when she had received the messengers, and had sent them out another way? For as the body without the spirit is dead, so faith without works is dead also." Some people claim that they are Christian, so that they feel they are going to heaven, but if they don't turn from their wicked lifestyle, then they aren't living up to their professed faith.
Salvation cannot be earned
On the other hand, we cannot earn our salvation: Eph 2:8-9, "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." But notice that in verse 10 it says, "For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them." I believe it's telling us that we can't be 'saved' by our works, but we are suppose to live a Godly life as a Christian. We aren't to claim we are Christians, and then go out and continue to live in the world.
Obey God's commandments
We must obey God's commandments: Matthew 7:21-23, "Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven. Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? And then will I profess unto them, I never knew you: depart from me, ye that work iniquity."
What are God's commandments? Matthew 22:37-40, "Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment. And the second is like unto it, Thou shalt love thy neighbour as thyself. On these two commandments hang all the law and the prophets." There are a lot of laws in the OT against things such as incest, adultery, worshipping idols, etc., but they all fall into these two categories. If a person loved God, they wouldn't be worshipping idols, misusing their bodies or minds for purposes that don't glorify God, and if a person loved his neighbor, he or she wouldn't steal, murder, or mistreat others. Jesus says that we prove our love for Him when we keep His commandments (John 14:15, 23, 24).
If we don't love the brethren, we abide in spiritual death: 1 John 3:14, "We know that we have passed from death unto life, because we love the brethren. He that loveth not his brother abideth in death. Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him." Mark 11:26 tells us that if we don't have mercy and forgive one another, it blocks us off from God forgiving us.
The unrighteous will not enter the kingdom of God: 1 Corinthians 6:9, "Know ye not that the unrighteous shall not inherit the kingdom of God? Be not deceived: neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor abusers of themselves with mankind, Nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners, shall inherit the kingdom of God." Of course, a person can come from that kind of a lifestyle, and be redeemed (that's why Jesus came to earth!), but that doesn't mean they can continue in their sins.
Sanctification (becoming more like Jesus)
Becoming more Christ-like is a growing process: Have you noticed how nobody becomes perfect in all their ways the moment they accept Christ? I believe there is a growing process we go through called sanctification. 1 Thessalonians 5:23, "And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ." 2 Timothy 2:22, "Flee also youthful lusts: but follow (pursue) righteousness, faith, charity, peace, with them that call on the Lord out of a pure heart."
The teaching Forgiven sinner or saint? will help show you the new person you are in Christ Jesus as a believer, and also how the power of sin is broken.