How do I stay strong in faith when my spiritual state goes up and down?

Ups and downs are completely normal, and no one stays at the same level all the time. What matters is to land a little higher after every low than before, and to keep asking God for that.

Anyone who works on their faith knows this feeling. At certain times, such as Ramadan, the heart is very close to God. Then everyday life returns, and during prayer the mind drifts to work and the next tasks. This is not a sign of weakness. It is a struggle that lasts as long as life itself.

Even the companions of the Holy Prophet Muhammad (saw) knew this. One of them felt spiritually uplifted in the presence of the Holy Prophet (saw), but fell back again at home, and so he thought he was a hypocrite. The Holy Prophet (saw) reassured him. Such changes are part of being human. No one can stay at the same height all the time.

What matters is the direction. The question is not whether you will sink again, but whether after Ramadan you fall back to exactly where you were before, or stay a little higher. Whoever stands a little higher after every rise and fall is on a good path, even if the progress seems small.

It is like certain birds that rise and dip in flight and yet keep climbing higher. Two things help with this. One is the prayer that God may lift you higher after every fall than you were before. The other is steadiness in small things, because God loves a good deed that is done regularly, even if it is modest.