“If ye then be risen with Christ, seek those things which are above, where Christ sitteth on the right hand of God.”  
Colossians 3:1

It matters what you think:
“For as he thinketh in his heart, so is he: Eat and drink, saith he to thee; but his heart is not with thee.”  Proverbs 23:7
And more often than not, your environment would influence the quality of thoughts you have. The people in that environment have a major role in shaping the kind of thoughts you allow and some times even the limitations you ascribe to your imaginations. In other words, the people you allow in your world would go a long way to determine your achievements in life, so the word of God minces no words as to who expects you to always be found with:
“Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?”  2Corinthians 6:14
Because when the world throws unbelief and fear at you, those who influence you would go a long way in determining how you respond:
“And being let go, they went to their own company, and reported all that the chief priests and elders had said unto them. And when they heard that, they lifted up their voice to God with one accord…” Acts 4:23-24
The best part is, the one you are always found with would either foster your unstoppable growth and increase or would deter it with sprouts of unbelief and thoughts of impossibilities:
“…With MEN this is impossible; but with GOD all things are possible.”  Matthew 19:26
Better to be found with God- a realm of absolute possibilities, than with men! He tells us in the main verse: “…seek those things which are above, where Christ sitteth…”