The Bible says,
1 John 1:7
But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin.
We must walk in the light, the light of the Holy Spirit. If we do this, God is patient, long suffering, gracious, and merciful to us... not imputing sin... willing to change us upon prayers of repentance and confession. However, if we walk away from the light of the Spirit and depart from the way of the cross... we will eventually come out from under the covering of the blood.
It isn't easy to lose your salvation. Christ died to be a sure foundation we can depend upon in our human weakness. Grace is there for the most terrible sin. God rejoices in forgiveness... forgiving sin and cleansing from sin brings God the highest glory.
In my opinion... the only "greasy grace" is that noting of grace in which you can easily slip through God's fingers.