The first thing is the mixture there oftentimes is in the experiences of true Christians; whereby when they have truly gracious experiences, and divine and spiritual discoveries and exercises, they have something else mixed with them, besides what is spiritual. There is a mixture of that which is natural, and that which is corrupt, with that which is divine. The great imperfection of grace, the feebleness and infancy of the new nature, and the great remains of corruption, together with our circumstances in this world, where we are encompassed with what tends to pollute us, expose to this.