What was Paul saying?

When Paul said,

"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." - Ephesians 2:8-9 

Paul was speaking of being saved by the gospel and our obedience to the gospel - by repentance, baptism in the name of Jesus, and receiving the gift of the Holy Ghost. (1 Corinthians 15:1-4, Romans 6:1-4, Acts 2:38, Mark 16:15-16, 2Thessalonians 1:8).

The works Paul is speaking of is the WORKS OF THE LAW (NOT baptism in the name of Jesus).

"But Israel, which followed after the law of righteousness, hath not attained to the law of righteousness. Wherefore? Because they sought it not by faith, but as it were by the works of the law..." - Romans 9:31-32 

"Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ...." - Galatians 2:16 

"This only would I learn of you, Received ye the Spirit by the works of the law, or by the hearing of faith?" - Galatians 3:2 

(Also Galatians 3:5, Galatians 3:10).

The Jews claim their righteousness as coming from their keeping of the law, thus boasting of their own righteousness. 

"Yea doubtless, and I count all things but loss for the excellency of the knowledge of Christ Jesus my Lord: for whom I have suffered the loss of all things, and do count them but dung, that I may win Christ, and be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:" - Philippians 3:8-9 

Paul was reminding the believers that they were saved by the GOSPEL and their obedience of the gospel; they were NOT saved by keeping the works of the law of Moses. Their righteousness is of God by faith, not their own righteousness which is of the law. 

Who is Paul speaking to? He is speaking to the church that had already repented of their sins, had been baptized in the name of Jesus for the remission of their sins, and had received the gift of the Holy Ghost.