There are many attempts made to get around the necessity of water baptism in the salvation of man. One such attempt I will deal here briefly is with Cornelius.
Heard - the word - believe
akouō ---- logos -- pisteuō
When the author of the Book of Acts (Luke) writes of people who have (1) heard (2) the word/s, and (3) believed it is
always in reference to people who are Christians.
Acts 2:22, 44
(22) Ye men of Israel,
hear these words; Jesus the Nazarene, a man approved of God among you by miracles and wonders and signs, which God performed through Him in your midst, as ye yourselves also know.
(44) And all who
believed were together, and had all things in common.
Acts 4:4, 32
(4) Howbeit many of those who
heard the word believed; and the number of the men was about five thousand.
(32) And the multitude of those who
believed were of one heart and soul: and not one of them said that anything belonging to him was his own; but all things were common property to them.
Acts 13:6-7, 12
(6) And when they had gone through the whole island as far as Paphos, they found a certain sorcerer, a Jewish false prophet, whose name was Bar-Jesus:
(7) Who was with the proconsul, Sergius Paulus, an intelligent man; who summoned Barnabas and Saul, and desired
to
hear the word of God.
(12) Then the proconsul, when he saw what was done,
believed, being amazed at the doctrine of the Lord.
Acts 19:10, 18
(10) And this continued by the space of two years; so that all those who dwelt in Asia
heard the word of the Lord, both Jews and Greeks.
(18) And many who
believed came, and confessed, and showed their deeds.
That Cornelius and the other Gentiles with him
heard the word and believed before their water baptism demonstrates they were Christians
before their water baptism.
Acts 10:43-44
(43) Of Him all the prophets bear witness, that through His Name whosoever
believeth in Him shall receive forgiveness of sins.
(44) While Peter yet spake these words, the Holy Spirit fell on all those who
heard the word.
Acts 15:7-8
(7) And when there had been much disputing, Peter rose up, and said unto them, Men, brethren, ye know how that a good while ago God made choice among us, that the Gentiles by my mouth should
hear the word of the gospel, and
believe.
(8) And God, who knoweth the hearts, bare them witness, giving them the Holy Spirit, even as unto us.