The following article is an excerpt from this book.

Since David prayed, “May my prayers be counted as incense before Thee” (Ps. 141:2, NASB), one thing we may conclude is that not all prayers are as incense.  Some in fact may be offensive to God.  Such are those prayers that are offered with wrong motives, which come from a heart with impure desires (Ja. 4:1-4).

Christ is the sweet aroma of our prayers.  If our prayers are not sweet before God it is because we have not allowed Christ to dwell in us and change us.  But if He is our reason for living, if He is loved by us and if we have let Him be Lord over us, to teach us and guide us and help us, and if we have let Him renew our mind, thus, if we have received from Him such precious graces of faith…