Being disingenuous carries with it the idea of one acting and speaking as if they are sincere about something when it is obvious, or at least God knows that they have other motives in play. For example we may think we are doing God a service with reference to something we are doing, but may very well deceive ourselves because we really have a strong self-interest at stake. This is plain hypocrisy and we've probably all fallen prey to it from time to time.
It is good to not pretend we're something more than we're not. We have no end for our potential and capacity for self-deception. If anyone thinks this is not the case than perhaps we haven't honestly examined ourselves in the light of God's will revealed in Scripture and in Jesus Christ. It is best to be modest about what we're all about, than to deceive ourselves as well as others into thinking that we're something that we're not.
Does this mean that we just accept impure motives, or even false motives for speaking and acting? No, of course not. But we do need to realize that we're people in Christ who are in development and hopefully growing towards Christ-likeness, but who still do sin. This endeavor towards Christ-likeness must be individually driven, but it also must exist in the context of community- accepting interdependence in that, and with dependence on God. This will involve ongoing repentance as well as the desire to grow and change, getting rid of that which is indeed disingenous and hypocritical.
What might you add here that could help us in this?