The early church was primarily Jewish. Notice, though that Jesus was not the Shepherd, but the elders were to shepherd or lead the flock or assembly.
No, the early church was not Jewish - the early Jewish church (under the Twelve) was "Jews and prosylites."
As was the early Body church (under Paul).
And GT is actually right on her one point there - at that point in Acts, Paul was addressing the following people...
Acts 20:17 And from Miletus he sent to Ephesus, and called the elders of the church. 20:18 And when they were come to him, he said unto them, Ye know, from the first day that I came into Asia, after what manner I have been with you at all seasons,
20:25 And now, behold, I know that ye all, among whom I have gone preaching the kingdom of God, shall see my face no more. 20:26 Wherefore I take you to record this day, that I am pure from the blood of all men. 20:27 For I have not shunned to declare unto you all the counsel of God. 20:28 Take heed therefore unto yourselves, and to all the flock, over the which the Holy Ghost hath made you overseers, to feed the church of God, which he hath purchased with his own blood. 20:29 For I know this, that after my departing shall grievous wolves enter in among you, not sparing the flock. 20:30 Also of your own selves shall men arise, speaking perverse things, to draw away disciples after them. 20:31 Therefore watch, and remember, that by the space of three years I ceased not to warn every one night and day with tears. 20:32 And now, brethren, I commend you to God, and to the word of his grace, which is able to build you up, and to give you an inheritance among all them which are sanctified.
That last passage is very similar in sense to these..
Romans 15:15 Nevertheless, brethren, I have written the more boldly unto you in some sort, as putting you in mind, because of the grace that is given to me of God, 15:16 That I should be the minister of Jesus Christ to the Gentiles, ministering the gospel of God, that the offering up of the Gentiles might be acceptable, being sanctified by the Holy Ghost.
And especially similar to these...
Romans 16:24 The grace of our Lord Jesus Christ be with you all. Amen. 16:25 Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began,
His mention of the inheritance there being the issue of what the building up of the Believer in a sound understanding of the doctrines of grace is meant to result in - in being able to do this here...
Colossians 3:23 And whatsoever ye do, do it heartily, as to the Lord, and not unto men; 3:24 Knowing that of the Lord ye shall receive the reward of the inheritance: for ye serve the Lord Christ.
The word of His grace enabling that result through this here...
Titus 2:11 For the grace of God that bringeth salvation hath appeared to all men, 2:12 Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world; 2:13 Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ; 2:14 Who gave himself for us, that he might redeem us from all iniquity, and purify unto himself a peculiar people, zealous of good works. 2:15 These things speak, and exhort, and rebuke with all authority. Let no man despise thee.
In Acts 20, Paul was speaking to elders of that assembly of Body members from Ephesus, and so on.
Which is why what he to them about wolves, etc., there, he repeated the basic thought of in writing here...
Ephesians 4:13 Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature of the fulness of Christ: 4:14 That we henceforth be no more children, tossed to and fro, and carried about with every wind of doctrine, by the sleight of men, and cunning craftiness, whereby they lie in wait to deceive;
The trail of interconnections between all those things as one doctrine (Establishment Truth), ever being a long, winding, and fascinating one.
Rom.5:8; 14:5.