Or in other words, when may a person be baptised?  The answer surely can be seen in the story of Philip and the eunuch:

Acts 8:35-39 “Then Philip opened his mouth, and beginning at this Scripture, preached Jesus to him.  Now as they went down the road, they came to some water. And the eunuch said, “See, here is water. What hinders me from being baptized?”

Then Philip said, “If you believe with all your heart, you may.”

And he answered and said, “I believe that Jesus Christ is the Son of God.”

So he commanded the chariot to stand still. And both Philip and the eunuch went down into the water, and he baptized him. Now when they came up out of the water, the Spirit of the Lord caught Philip away, so that the eunuch saw him no more; and he went on his way rejoicing.” 

“If you believe with all your heart…” This is true faith. It is found in the heart, not in the head! But let’s not be too judgmental on this point. One person’s reaction when they come to believe may appear quite different from that of another. One may display a lot of emotion, whereas another may be more reserved, yet still have a deep faith.

Being filled with the Holy Spirit is good evidence that a person believes with all their heart.

Acts 10:44-48 While Peter was still speaking these words, the Holy Spirit fell upon all those who heard the word. And those of the circumcision who believed were astonished, as many as came with Peter, because the gift of the Holy Spirit had been poured out on the Gentiles also.  For they heard them speak with tongues and magnify God.

Then Peter answered, “Can anyone forbid water, that these should not be baptized who have received the Holy Spirit just as we have?”  And he commanded them to be baptized in the name of the Lord. Then they asked him to stay a few days.

So in this case, when Peter hears the men speak in tongues he knows they are true believers. They were magnifying God, showing true heart faith, qualifying them for baptism.

The story of Simon the sorcerer (Acts 8:9-24) is instructive. He was baptised, but the baptism was not effective in his case because his heart was not right with the Lord.

The devil has tried hard to obscure some of this truth. Going back to Acts 8:35-39, v 37 gives the crux of the issue: “ Then Philip said, “If you believe with all your heart, you may.” And he answered and said, “I believe that Jesus Christ is the Son of God.” Is this verse in your Bible? We’ll discuss this issue another time!