Why can't Christians agree?

The claim under examination: among Christians who all affirm Christ and grace, which reading of salvation best fits Jesus' own promises and allows real assurance?

Standard · preponderance of the evidence, not proof

◆ The case for

Free Grace offers the most direct assurance, resting it on Christ's promise at the moment of faith.
It takes Jesus' present-tense promises at ordinary force, and keeps eternal life distinct from discipleship and reward.
The other systems are serious too — Catholic, Orthodox, Reformed, Arminian, Lordship — each a real attempt to fit the whole Bible.

◇ The case against

The cheap-grace objection. Critics cite James, "faith without works is dead," and the danger of false professions.
Perseverance and works as evidence. Many hold that genuine faith necessarily endures and shows fruit.
No system gets a free pass, Free Grace included; it must show its distinctions come from the text, not convenience.

The verdict

DisprovenUnlikelyPlausibleStrongly supportedEstablished

That these traditions differ mainly by interpretation, not by reading different Bibles, is strongly supported. That they offer the same kind of present assurance is contradicted by their own teaching. Free Grace offers the most direct assurance; whether it is the correct reading is supported by Jesus' direct promises, but still contested.

If you read nothing else

Where do you finally look to know you have eternal life — at Christ's promise, or partly back at yourself?

Everyone here affirms Christ and grace. The deepest fault line is assurance. If you must wait for enough fruit, or fear losing it, or keep a sacramental standing, some of your confidence rests on you. Free Grace says Christ's promise itself is enough. That is the question the conclusion has to answer.