peithō

This is the outward facing side of the word: one person works on another's mind to bring them around. The means are not built into the word. It covers honest reasoning, as when Paul spends three months in a synagogue making his case, and it covers pressure, payoff, and crowd manipulation, as when chief priests talk a mob into asking for a criminal's release. The word names the attempt to move someone, not a verdict on whether the cause was good.

Because persuasion aims at a result, the same word can lean toward the effort or toward the success, and it can shade into simply smoothing a person over:

• sometimes it names the attempt, arguing and urging with no promise of winning
• sometimes it names the achievement, a crowd actually brought around
• sometimes it names buying goodwill rather than changing a mind, getting an official onside
• once it turns inward, quieting a troubled heart before God

Context, not the word, tells you which. That range is why one verb can carry Paul's confident description of his own work, persuading people because he knows what it is to fear the Lord, and also his uneasy question in Galatians 1:10 about whether he is out to win over people or God. The same family gives Greek its ordinary words for believing (πιστεύω) and for settled confidence (πεποίθησις), which is why persuading and trusting are never far apart here.

Greek had a special form of this verb, past in shape but present in force, and it took on a job of its own: being in a settled state of confidence. When the New Testament uses that form the sense is not the act of persuading anyone but the condition of trusting, of leaning on someone and counting on them to hold.

What the New Testament cares about is where that weight is placed, and it can be placed badly or well. People lean on wealth, on their own record of righteousness, on a strong man's weapons, on their religious credentials. They also lean on God's faithfulness to finish what he started, on the Lord himself, and on the God who raises the dead. The verb is the same in both directions, which is what makes the contrast so pointed when Paul sets confidence in his own standing against confidence in Christ.

This is also the New Testament's deepest tie to the Old Testament language of trust. When Jewish scholars turned their scriptures into Greek, this was one of the words they reached for to carry the Hebrew verb for trusting and feeling secure (בָּטַח), reaching past the ordinary word for believing (πιστεύω). That history is why a verb whose everyday sense was winning an argument carries such warmth here. It is not an argument won but a weight gladly handed over.

Here the action has turned inward and finished. Someone has been brought to a settled conviction and now holds it. This is what the receiving end of persuasion looks like once persuasion is done, but the attention falls on the certainty rather than on who did the convincing.

Paul reaches for it at his most assured: that nothing in creation can separate believers from God's love, that he knows the one he has trusted, that no food is unclean in itself. It also covers a quiet personal certainty, as when he says he is sure of the sincere faith he saw in a mother and grandmother, and a whole crowd's fixed belief that John really was a prophet. A verse may name what produced the conviction or leave it unsaid. Either way the matter is now held as settled.

When the word describes someone yielding to a voice rather than weighing an idea, it shades from being persuaded into obeying. That overlap is the point, not a blur. To comply here is to be won over by someone or something you have accepted as worth following, rather than simply to submit because you were told to.

It runs across a wide range:

• followers attaching themselves to a would-be leader and his cause
• a soldier siding with the ship's officers against Paul's warning
• horses answering the bridle in the mouth
• readers urged to go along with those who lead them
• people who refuse to be moved, who would not believe even if someone rose from the dead

Greek had blunter words for obedience under authority: one for listening the way a child or a servant listens (ὑπακούω), and one for placing yourself under someone (ὑποτάσσω). When a New Testament writer passed over those and chose this verb, the choice usually mattered, because this word keeps the note of consent inside the compliance. The negative side works the same way. Paul's word for refusing the truth in Romans 2:8 is this verb's own negative twin (ἀπειθέω), so disobedience there is a refusal to be won over, not just a broken rule.