How can I stop being lukewarm to God?

I remember during my childhood, I always attended church and was active in church activities. I always felt God’s presence was always with me since He always answered my prayers.
But when I am growing up, sometimes
sometimes I forget to go to church and pray. I am just praying or going to church when I need something from God. I’m lazy. My mind is always on my cell phone and my friends, where we can always have fun. I know what I’m doing is wrong, but my spirit is drained.
How can I stop being lukewarm to God?