My heart is stirred by a noble theme
as I recite my verses for the king;
my tongue is the pen of a skillful writer.
2 You are the most excellent of men
and your lips have been anointed with grace,
since God has blessed you forever.
3 Gird your sword on your side, you mighty one;
clothe yourself with splendor and majesty.
4 In your majesty ride forth victoriously
in the cause of truth, humility and justice;
let your right hand achieve awesome deeds.
5 Let your sharp arrows pierce the hearts of the king’s enemies;
let the nations fall beneath your feet.
6 Your throne, O God,[c] will last for ever and ever;
a scepter of justice will be the scepter of your kingdom. Psalm 45:1-6
Lillie-Put 
What I seem unable to achieve…
Well I guess that would depend on your definition. I think sometimes we replace the idea of excellence with and unachievable idea of perfection. I think excellence is more about the willingness to attempt and work at something than it is about the attainment of a thing. I think it has more to do with including God in a thing so He can make up the difference rather than needing to get it all fixed ourselves.