He that is faithful in that which is least is faithful also in much:
and he that is unjust in the least is unjust also in much. Luke 16:10
The Lord God sees all.
A little thing like holding the door open for someone, helping your neighbor, praying for a lost soul.
Those things matter.
They might take you a second or longer.
There are no merits. Jesus talks of rewards in Heaven. Do we understand what that means?
If we do things to be seen of men, we lose our reward.
The rewards are greater than we can ever imagine.
For since the beginning of the world men have not heard, nor perceived by the ear,
neither hath the eye seen, O God, beside thee, what He hath prepared for him that waiteth for Him.
Isaiah 64:4
It is more like a gift. He gives us gifts and we give Him gifts.
Call it what you will, every little thing matters. Every deed. Every thought, every intention.
For God shall bring every work into judgment, with every secret thing,
whether it be good, or whether it be evil. Ecclesiastes 12:14
Everything gets recorded. Every single thing, whether it be great or small. The small things matter.
And I saw the dead, small and great, stand before God; and the books were opened:
and another book was opened, which is the book of life:
and the dead were judged out of those things which were written in the books, according to their works.
And the sea gave up the dead which were in it;
and death and hell delivered up the dead which were in them:
and they were judged every man according to their works. Revelation 22:12-13
Even the little things matter.