Jennifer Lopez opens up about keeping her marriage to Marc Anthony strong.

"I'm still figuring it out as I go along," Lopez tells InStyle magazine. "How do two totally different people come together and make one life and say they'll do it forever and ever? I mean, I've tried it. This is my third time. I don't even think I tried in my other marriages, which was immature and not knowing better. ... I believe that in life you learn through experience. I'm old enough to know now that relationships take work. That it's not an easy thing."

Lopez and Anthony wed in 2004 and have twin babies, Max and Emme. She says of her relationship with hubby, "We're always together. ... I respect him so much."

The singer/actress remains inquisitive about love, revealing that she enjoys reading books on relationships. "It's the never-ending question -- what is the key to love?"

For more with Lopez, check out the latest issue of InStyle magazine's 15th anniversary issue, on newsstands Friday, August 21.