I really love this quote although I can see how it may be easily taken the wrong way!...I'm sure it definitely does not mean accepting any kind of abuse (which is never okay) or not being proactive in finding solutions to challenges.
To me it means that at times we can spend so much energy pushing against challenges, like going against a strong wind: resisting them, spending a lot of our energy on feeling resentful and angry towards having them. Sometimes they can feel like unwelcome intruders that wreck our fantasy of what our 'perfect' day should have been.
"Accepting" challenges can mean
not making them conditional on our experience of inner peace and joy; but ultimately (once our initial reactions subside) being able to refocus on finding peace, joy, and beauty in our being and faith, while we work on coping the best we can...