Amides are more acidic than amines because of the presence of lone pair of electron on N -atom of $- NH _2$ group. But this lone pair of electrons is involved in resonance as shown below : Due to $+R$ effect availability of lone pair of electrons of N of $- NH _2$ group decreases. As a result acid amide is much weaker base than amines. Because of the positive charge on N -atom as a result of resonance, N can lose easily a proton from N and behaves as a weak acid.