In fairness to Trump, there is no solution to the Israel/Palestine conflict that doesn't require at least one side to be completely removed from the area. You can call it ethnic cleansing, although unlike most forms of ethnic cleansing it doesn't have to involve genocide.
Religion means neither side can leave the area voluntarily as they believe they are entitled to occupy it and the other side isn't.
You could remove this problem by eradicating the religions from the population but this would take thousands of years.
The alternatives are an unpalatable forced removal of one or both sides, either by killing them all or forcible relocation, or a continuation of the on/off conflict which flits between terrorist attacks and all-out warfare. There is no peaceful, just resolution that will be accepted by both sides.
Trump's mistake is that his proposal is very firmly in Israel's favour. A better solution would be for the US to occupy the whole of Israel/Palestine and force both parties out. Clear the whole area and force the population to relocate to a country that will accept them. The main benefit of this is both sides lose and (if any sense is applied) the evicted people will be transferred to countries far apart from one another.
The cleared territory could be filled with landmines to discourage either side trying to get back in, and be periodically bombarded from the air by the US military.