A Full Reward

2 John 1:8. Look to yourselves, that we lose not those things which we have wrought, but that we receive a full reward.

This one verse tells us three things.
There is a reward for the righteous.
A person made righteous in Christ can suffer loss for failure to continue in well doing.
One can fall short of a full reward as a result of neglect.

Hebrews 2:3. How shall we escape, if we neglect so great salvation; which at the first began to be spoken by the Lord, and was confirmed unto us by them that heard Him.
1 Timothy 4:14-16. Do not neglect the spiritual gift within you, which was given to you through prophecy with the laying on of hands of the elders.
Practice these things—be absorbed in them, so that your progress may be clear to all.
Give attention to yourself and your teaching.
Persevere in these things, for in doing so you will save yourself and those who hear you.
2 Peter 1:12. For this reason I will not be negligent to remind you of these things always, though you know and are established in the present truth.

Psalm 58:11. So that men will say, Surely there is a reward for the righteous;
Surely He is God who judges in the earth.

Galatians 5:22-26. But the fruit of the Spirit is love, joy, peace, longsuffering, kindness, goodness, faithfulness, Meekness, temperance: against such there is no law. And those who are Christ’s have crucified the flesh with its passions and desires. And those who are Christ’s have crucified the flesh with its passions and desires. If we live in the Spirit, let us also walk in the Spirit. Let us not become conceited, provoking one another, envying one another.

Brains isn't a big part of the equation, but an honest and good heart.

Luke 8:15. But that on the good ground are they, which in an honest and good heart, having heard the word, keep it, and bring forth fruit with patience.