The common view is that salvation is exactly the same throughout the Bible. Most preachers will tell you, "People in the Old Testament were saved by looking toward the cross and people in the New Testament are saved by looking back to the cross." Such statements satisfy the professing Christians that rarely read their Bible, much less study it. But Christians who take the Bible seriously have a hard time just accepting that cliché when they read passages like this:
(21) From that time forth began Jesus to shew unto his disciples, how that he must go unto Jerusalem, and suffer many things of the elders and chief priests and scribes, and be killed, and be raised again the third day.
(22) Then Peter took him, and began to rebuke him, saying, Be it far from thee, Lord: this shall not be unto thee.
Why would Peter do such a thing? Because he had no clue what Jesus was talking about!
(31) Then he took unto him the twelve, and said unto them, Behold, we go up to Jerusalem, and all things that are written by the prophets concerning the Son of man shall be accomplished.
(32) For he shall be delivered unto the Gentiles, and shall be mocked, and spitefully entreated, and spitted on:
(33) And they shall scourge him, and put him to death: and the third day he shall rise again.
(34) And they understood none of these things: and this saying was hid from them, neither knew they the things which were spoken.
People in the Old Testament were saved by looking toward the cross? The twelve weren't even looking toward the cross! The fact that they had been preaching the gospel (Lk. 9:1-6) for three years BEFORE Christ began to speak to them about His death, burial, and resurrection proves that there are different gospels in the Bible. They preached the gospel of the kingdom to Israel which was the good news that their prophesied kingdom was at hand (Matt. 4:23; 10:5-7). There is only one gospel to be preached in this present age and Christ gave it to the apostle Paul by revelation (Gal. 1:6-12). Paul preached the good news that Christ died for our sins, was buried, and rose again the third day (1 Cor. 15:1-4).
I hope the following five points will help you better understand the dispensational truth of the word of God concerning salvation.
1. The basis of salvation in every age is the blood of Christ. The death, burial, and resurrection of Christ is the only basis upon which God can save a sinner in any age. It was planned before the world began and prophesied in the Old Testament. However it was not understood or preached as good news until after it was accomplished. Its full meaning was a mystery revealed through Paul’s gospel (Gal. 1:11-12). The cross-work of Christ is the secret to God’s dealings with sinners in every age but it was not fully revealed until this present age. By faith the Old Testament saints obeyed the commandments of the law and brought the required sacrifices for their sins. Through forbearance God allowed the blood of bulls and of goats (that cannot take away sins, Heb. 10:4) to cover sins because He knew the blood of Christ would be shed for the remission of sins (Rom. 3:25).
2. The condition for salvation in every age is essentially faith. Without faith it is impossible to please God (Heb. 11:6). The eleventh chapter of Hebrews teaches that men both before the law and under the law obtained a good report from God by faith. Why did God accept the sacrifice of Abel? He brought it by faith (11:4). God has never and will never accept the works of sinful flesh (Jn. 6:63; Rom. 8:8).
3. The object of faith in every age is the word of God. Faith is not just believing. Everybody believes in something but not everybody has faith (2 Thess. 3:2). Faith is believing the word of God (Rom. 10:17).
4. The content of faith is not the same in every age because God has not said the same thing to man in every age. God has not always told men not to do any works but to simply trust the finished work of Christ alone for salvation as He does in this age. In times past He required works of men to prove their faith and He will do so again after this age. If God requires works real faith will seek to do those works (Jam. 2:14-26). But the works in and of themselves have never and will never save a sinner. Why doesn’t God require us to do works to prove our faith in this age? We are justified by "the faith of Christ" (Gal. 2:16) and His faith is perfect and proven!
5. The results of faith are not the same in every age because God has not given believers in every age the same position, blessings, and destiny. There is doctrine revealed in Paul’s epistles concerning the position, blessings, and destiny of the body of Christ that we do not find in the Gospel records or Hebrews through Revelation (which concern kingdom saints) and we must not try to force things that are different to be the same. This information is only found in Paul’s epistles because he is the one to whom the glorified Christ from Heaven revealed it. Christ committed these truths to Paul (not the 12 apostles who were apostles to the 12 tribes of Israel, Matt. 19:28) to make it known. Our position as members of the body of Christ means that nothing can separate us from the love of God (compare Rom. 8:35-39 with John 15:10 and Jude 21). We are sealed with the Holy Spirit (Eph. 1:13) and therefore would never have to pray, "take not thy holy spirit from me" as David did (Ps. 51:11). The Spirit of the Lord will never depart from us as He did from King Saul (compare 1 Sam. 16:14 with Eph. 4:30). Our blessings are spiritual and in heavenly places (Eph. 1:3, compare with Israel’s material blessings on earth in Deut. 28). And we did not obtain our blessings by keeping the commandments of the law but by being in Christ. The body of Christ is destined to reign with Christ in heavenly places (Eph. 2:6-7). It is Israel that is destined to reign on the earth (Ex. 19:5-6; Rev. 5:10).