Bism Illah wa as salaamu alaykum wa Rahmat Allah wa Barakatuh.
When you're tired and the adhaan for fajr goes, and you waver about whether to drag yourself up and pray or just stay in bed... consider the price of the prayer.
You will have to get out of your bed, go to the bathroom, make wudhu, and then perform the prayer. It may take as little as 5 to 10 minutes of your time.You can pay the price of the prayer in those few minutes and, in turn, honor your debt to Allah....and to yourself, because the prayer is for your benefit. Your day starts with a feeling of peace and accomplishment.Once finished, if you are still tired you can go back to bed and rest easily, knowing your debt has been paid.
However if you stay in bed, you will get up later knowing that you intentionally missed a prayer - something that Allah has commanded you to perform on time . The thing you will first be questioned about on The Day of Account. The price you have to pay for not praying might add up to this. You may have a weight of guilt somewhere inside you because you haven't done what Allah has commanded you as obligatory. You may seek forgiveness from Allah and be disappointed in yourself for your lack of discipline and giving in to shaytaan's whispers. You may make up the prayer later, but you know that it doesn't bear the same reward as praying it at it's designated time, in obedience to Allah's call. You may even fall into despair, losing respect and hope in yourself. You may put internal pressure on yourself to resolve to pray all your prayers on time in the future. That's a lot of stuff. You are in a state of deficit - because in making this choice, you pay a high price and you don't fulfill your debt to Allah or yourself.
But if you take the easy path, you will simply get up straight away, make wudhu and pray. If your tired, you can always go back to bed. After all, for the price of 5 or 10 minutes of your time, you will have none of the headache, heartache, or guilt to deal with. Isn't 5 minutes of prayer easier than the weight of your status with Allah?
So I say to you all, when you are wavering, take the easy path....for it leads to success.