If the commonly uttered notion that ‘all you need is love’ were true, then God’s amazing love for all the world would surely suffice.
But though God is love, love is not, I repeat, is not god.
‘All you need is love’ is idolatry because it replaces God with an attribute of God. It slices God into bits and makes one bit the only bit.
The real aim and purpose of suggesting that love is all you need is to replace God with personal sentimentality. And it is idolatry.