Hosea 7:15

‘Though I have taught and strengthened their arms,

Yet they do devise mischief against me.'

And yet it was YHWH and not Baal Who had taught them and made their arms strong. This may refer to the fact that He had brought them to young adulthood, rearing them as His children (compare Hosea 11:3). Or it may refer to Him as having made them strong for battle (compare Psalms 18:32). Either way the idea is that they owed everything that they were (as possessors of the land and landowners in Israel) to Him, and yet all they had done was devise mischief against Him.