The calling of the believer in Christ while interacting with unbelievers and adherents to other religions is to strive to get to the conviction of sin, which only the Holy Spirit can work, but also should guide our approach.  Stating it simply, in the unregenerate person’s religious life and efforts, rather than their approaching God they are in fact rebelliously running from Him and raging against Him.  This is very hard to lovingly communicate because of the spiritual blindness of the natural heart and the protection of oneself against any exposing.

Herman Bavinck has written the following,

The sense of the divine and the seed of religion hidden therein are thanks to God’s general revelation and redound as an unfathomable blessing to the human race.  But the manner in which this religious sense within manifests itself in representations and affections, and in outward acts of worship, is counterfeited and corrupted everywhere. (Guidebook for Instruction in the Christian Religion, 26)

So we see the evidence of human corruption most clearly in the religious distortions and departures from the truth.  The strength of and devotion to the suppression of the religious impulse and sense is eerily reflective of the religious bent of the human heart.  Bavinck again,

But the fact remains the same: In the long course of its civilization, humanity has not glorified God nor given thanks to God.  In the first place, in all nations, we find idolatry and the production of graven images.  Alongside this idolatry, then, are all sorts of false conceptions about humanity and the world, sanctification and sin, and about the present life and the life to come.  Third, all religions distinguish themselves as religions separate from Christianity through the endeavor of the individual to acquire salvation through the effort of human strength. (Guidebook for Instruction in the Christian Religion, 26)

Each of these three aspects furnishes abundant evidence of the religious nature of people.  They are found in different ways and to different degrees in every religion and individual adherent, but they are there none-the-less.  What a powerful reality general revelation is!

Yet, general revelation is not enough!  We need more than a broad awareness about the existence of God and the awareness of our awareness of Him.  We need salvation. Bavinck concludes his chapter on General Revelation,

General revelation awakens and nourishes the need for a special revelation.  If there is to be salvation for mankind and the world, then general revelation illuminates its necessity.  It is already entwined within this special revelation; it will be a work of redemption, an act of special grace.  no people and no religion have been satisfied with the general revelation of God in nature and history.  All of them felt the need for another, further, disclosure of God than that which comes to them from nature. (Guidebook for Instruction in the Christian Religion, 27)