Have you ever heard some preacher say: “There are many things in the Bible which are hard to understand but, thank God, the plan of salvation is as simple as can be.”
Well the plan of salvation is simple IF we obey II Timothy 2:15, “rightly dividing the Word of truth.” Otherwise it is far from simple.
The Apostle Paul wrote: “We conclude that a man is justified by faith without the deeds of the law” (Rom. 3:28). Yet James wrote: “By works a man is justified, and not by faith only” (James 2:24).
Again, at Sinai God said to Israel through Moses: “If ye will obey My voice indeed, and keep My covenant, then ye shall be a peculiar treasure unto Me above all people …” (Ex. 19:5). But our Lord said, as He sent His apostles to witness for Him that, “He that believeth and is baptized shall be saved… and these signs shall follow them that believe: in My name shall they cast out demons, they shall speak with new tongues…” etc. (Mark 16:16-18). Thus, according to their “great commission” water baptism was required for salvation and miraculous signs were the evidences of salvation.
Confusing? Contradictory? Not if we “rightly divide the Word of truth.” It was after “the law was given by Moses,” after our Lord’s earthly ministry, after the commission to the twelve, that God raised up another apostle, Paul, and sent him forth with “the gospel of the grace of God” (Acts 20:24).
It was Paul who was sent to declare: “But NOW, the righteousness of God without the law is manifested…” (Rom. 3:21). “To him that worketh not, but believeth on Him that justifieth the ungodly, his faith is counted for righteousness” (Rom. 4:5). “Therefore, being justified by faith we have peace with God through our Lord Jesus Christ” (Rom. 5:1). source