Translators may omit the connector For at the beginning of this verse.

Just as you purposed to go astray from God: The Greek does not really go quite so far as to say the people were “determined to turn away from God” (Good News Translation, Contemporary English Version). New Revised Standard Version “you were disposed to go astray from God” comes closer, and Moore is even closer with “you had the idea of straying from God.” The people’s going astray was a result of their carelessness or negligence rather than the result of a conscious decision to “turn away.”

Return with tenfold zeal to seek him: The idea of seeking God is frequent in the Old Testament, and is usually expressed in Good News Translation by “turn to God” or “serve God.” Since the idea of turning back is stated at the beginning of this line, both expressions are used here in Good News Translation, and to good effect. How does anyone seek God other than by going to him? And how does anyone do this other than by serving him or worshiping him? It is certainly not the idea of looking for him, as if someone were looking for a lost coin. Even though the idea of determination is not necessarily found in the Greek of the first line of this verse, the idea is present here in the phrase with tenfold zeal. Good News Translation has “with ten times more determination.”

An alternative model for this verse is:

• Just as you were once inclined to wander away from God, turn back now, and serve him with ten times the [or, even greater] determination.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on The Shorter Books of the Deuterocanon. (UBS Helps for Translators). New York: UBS, 2006. For this and other handbooks for translators see here.