Uninvited

³⁷Now when they heard this they were cut to the heart, and said to Peter and the rest of the apostles, "Brothers, what shall we do?" And Peter said to them, "Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit. ³⁹For the promise is for you and for your children and for all who are far off, everyone whom the Lord our God calls to himself."
     - Acts 2:37-39

³⁶And as they were going along the road they came to some water, and the eunuch said, "See, here is water! What prevents me from being baptized?" ³⁸And he commanded the chariot to stop, and they both went down into the water, Philip and the eunuch, and he baptized him.
     - Acts 8:36-38

²⁷When the jailer woke and saw that the prison doors were open, he drew his sword and was about to kill himself, supposing that the prisoners had escaped. ²⁸But Paul cried with a loud voice, "Do not harm yourself, for we are all here." ²⁹And the jailer called for lights and rushed in, and trembling with fear he fell down before Paul and Silas. ³⁰Then he brought them out and said, "Sirs, what must I do to be saved?" ³¹And they said, "Believe in the Lord Jesus, and you will be saved, you and your household."
     - Acts 16:27-31

When you read through the book of Acts, one of the things you will notice is that the apostles never employed the use of altar calls. They never, as far as I can tell, issued an "invitation" or asked their hearers if they were ready to "make a decision." Some heard their message and wanted to kill them, and no amount of coaxing or inviting would have had any impact on them. Others were "cut to the heart" and would not rest until they had received a satisfactory response to the burning question in their hearts… What must we do to be saved?

We do a great disservice to the gospel of Jesus Christ when we reduce it to an illustration or a formulaic process wherein we present a certain set of propositional truths and then solicit a response from our unconverted target. The gospel isn't a how-to for salvation. It is nothing less than a proclamation of the lordship of Jesus Christ, the Son of God, who died to take away the sin of the world. People will certainly respond to this message, but not because we've asked them to. If your "gospel presentation" requires you to ask for a response, you're probably presenting something other than the gospel.

Manfishing

¹⁸While walking by the Sea of Galilee, he saw two brothers, Simon (who is called Peter) and Andrew his brother, casting a net into the sea, for they were fishermen. ¹⁹And he said to them, "Follow me, and I will make you fishers of men." ²⁰Immediately they left their nets and followed him. ²¹And going on from there he saw two other brothers, James the son of Zebedee and John his brother, in the boat with Zebedee their father, mending their nets, and he called them. ²²Immediately they left the boat and their father and followed him.
     - Matthew 4:18-22

Jesus calls Peter, Andrew, and the Sons of Thunder to follow him and he will make them "fishers of men." The obvious reference is to their prior occupation, that Jesus would employ them in pulling men into the boat instead of fish. Thomas Boston encourages us to take it one step further, considering why the men they were after would be compared to fish:

BUT WHY ARE UNCONVERTED MEN COMPARED TO FISH IN THE WATER?

Among other reasons, they are so because as the water is the natural element of fish, so sin is the proper and natural element for an unconverted soul. Take the fish out of the water, it cannot live; and take from a natural man his idols, he is ready to say with Micah, Ye have taken away my gods, and what have I more? The young man in the gospel could not be persuaded to seek after treasure in heaven, and lay by the world. It is in sin that the only delight of natural men is; but in holiness they have no more delight than a fish upon the earth, or a sow in a palace.

Oh, the woeful case of a natural man! Bless the Lord, O my soul, that when that was thy element as well as that of others, yet Christ took thee in his net, held thee, and would not let thee go, and put another principle in thee, so that now it is heavy for thee to wade, far more to swim in these waters.
     - Thomas Boston, The Art of Manfishing

The unconverted man loves sin and hates righteousness in much the same way that fish love the water and hate dry land. No amount of coaxing or persuasion can effectively convince a fish to forsake the water in favor of dry land. A fish may, for a short time, force himself to live out of the water. This will not last long. He may die, but more likely he will find a way back into the water for which he is most naturally suited. If a fish is to exist permanently out of the water, he must become something other than a fish.

This is what the Holy Spirit does in man's conversion. Through the proclamation of the Word (1 Cor. 1:23) and the working of the Holy Spirit (John 3:8), he who is spiritually dead is made something other than a dead man. The rebel who hates God and loves sin is made to love God and hate sin. Anything less than this and all you have is a convert in name only, who is no more suited for the Kingdom of God than a fish for dry land.