1Moreover, brethren, I would not that ye should be ignorant, how that all our fathers were under the cloud, and all passed through the sea;
2And were all baptized unto Moses in the cloud and in the sea;
3And did all eat the same spiritual meat;
4And did all drink the same spiritual drink: for they drank of that spiritual Rock that followed them: and that Rock was Christ.
It is important to identify exceptional use of words when trying to extract a biblical definition from the context of a Scripture passage. This is certainly the case in 1 Corinthians 10:1-4. Baptism is always a reference to immersion with no exceptions. Here, Paul is using the word not in its denotative sense, but in a figurative sense.
The Israelites did not by any means get wet as they passed through the Red Sea. Passing through the sea was figurative as well as eating the same spiritual meat — manna (see John 6). The spiritual drink was the water from the rock, not the fruit of the vine. These pertain to the two ordinances of the church, baptism and communion, figuratively. In this sense does the word church apply to Israel in Acts 7:58.
Acts 7:38 This is he, that was in the church in the wilderness with the angel which spake to him in the mount Sina, and with our fathers: who received the lively oracles to give unto us:
Non-dispensational theology might use equivocation to claim the promises for Israel to be applied to the church by this passage, but there is no way to compare the qualities of the church to the nation of Israel. Jews and Gentiles were separate until they became one in a new institution — the church:
1For this cause I Paul, the prisoner of Jesus Christ for you Gentiles,
2If ye have heard of the dispensation of the grace of God which is given me to you-ward:
3How that by revelation he made known unto me the mystery; (as I wrote afore in few words,
4Whereby, when ye read, ye may understand my knowledge in the mystery of Christ)
5Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit;
6That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel:
7Whereof I was made a minister, according to the gift of the grace of God given unto me by the effectual working of his power.
8Unto me, who am less than the least of all saints, is this grace given, that I should preach among the Gentiles the unsearchable riches of Christ;
9And to make all men see what is the fellowship of the mystery, which from the beginning of the world hath been hid in God, who created all things by Jesus Christ:
10To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God,
The Gentiles were to become fellowheirs in the same body (Eph. 3:6) and this is now revealed in the church (Eph. 3:10).
In Acts 7:58, church is used in a figurative sense, and in 1 Cor. 10:4 it has a figurative baptism and communion.