The saving gospel is the good news that Jesus died for our sins, was buried, and rose again. We obey the gospel (II Thessalonians 1:8; I Peter 4:17) by repentance (death to sin), water baptism in the name of Jesus Christ (burial), and the baptism of the Holy Spirit with the initial sign of speaking in tongues as the Spirit gives the utterance (resurrection).
I Corinthians 15:1-4 - "Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures."
Acts 2:4 - And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.
Acts 37-39 - "Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do? Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost. For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call."
Romans 6:3-4 - "Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? Therefore, we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life."