Imān is something that will always fluctuate. It will never remain at the same level constantly. Your Salah should be non-negotiable. Do not compromise on it at any cost. If you are going out, try to fix your salah first. Even if your Imān is low, don't leave it. Even if you're feeling spiritually low, that should not lead to missing one prayer. Let it not happen that missing one prayer leads to missing all five prayers. Try to pray, strive to pray all of them. When you start praying even one, gradually it will become a habit. Secondly, never abandon your morning and evening adhkar. Make it a daily habit. Thirdly, constantly be in Istighfar. Try to do as much Istighfar as possible. Dhikr softens the heart. Even when your Imān is low, your heart becomes soft through dhikr — and things get better. And remember two things: 1. If you are low in Imān, have non-negotiable. Try to stay away from certain things. Like even if my Imān is low right now or ever becomes weak, I'll never do this things — no matter what happens. 2. And when you are high in Imān — of course, such moments come where you feel spiritually strong or emotional — try to do as much good as possible during that time.