Dangerous only if you're not serious about God. I know in my life I have prayed this prayer not once but several times. The dangerous part about it is God usually answers it in ways we may not expect.
The first time I prayed this prayer was as a young believer and boy did God answer that prayer. Over a period of time God searched me and showed me the real condition of my heart. It wasn’t a pretty site. What it did though was it drove me closer to Him. I realized given the true condition of my heart that I desperately needed Him.
Throughout the course of my walk with God I have prayed this prayer and God has been faithful to answer - He tested me. Tests came in the form of illness, business set-backs, relational issues or delayed gratification. Each time I grew in my understanding of who God is. But just the same the answer to my prayer was not something I expected or even liked at the time.
One thing was certain every time I prayed this prayer my anxious thoughts were revealed and my offensive ways were exposed. All told however, it always led me to the realization that there’s only one way to life everlasting and that’s being in fellowship with my God.
True it is one dangerous prayer but one that I would highly recommend.