Romans 12:2 And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.
Christians should have the most optimistic, positive attitude, disposition, and outlook on life. Negativity and pessimism seem to prevail in our world, but Jesus has overcome the world and allows us to share in His victory. We should be victory minded and be “can do” people. We have been given world overcoming faith 1 John 5:4 and the Greater One Who lives in us 1 John 4:4.
Negativity is the bend/bias of the natural mind. It is the default setting of an unrenewed mind. Without renewing the mind it will tend toward negativity. Guess what, though, we can renew our minds until the mind of Christ within our spirit becomes our everyday thinking mind Romans 12:1-3; 1 Corinthians 2:16. We have the mind of Christ as a provision of His Grace so that everything in our mind can get fixed.