For this very reason, make every effort to add to your faith goodness; and to goodness, knowledge
NIV
For this very reason, adding your diligence [to the divine promises], employ every effort in exercising your faith to develop virtue (excellence, resolution, Christian energy), and in [exercising] virtue [develop] knowledge (intelligence)
AMP
And beside this, giving all diligence, add to your faith virtue; and to virtue knowledge;
KJV