Mutual affection between loving partners is not considered sinful by most Christian denominations.It does mean, however, that we should be careful about what is in our hearts and to make sure we maintain self-control when kissing.
I’m a big believer in the school of you-don’t-know-it-until-you’ve-done-it. We were both humanists (which is a fancy term for do-gooder atheists) of Jewish descent. Rachel also told me that our marriage is a resounding success, and I believe her.
First Corinthians says, Christian teenagers and unmarried singles are advised to spend time in prayer and think through what they are doing, and to remember that just because an action is permissible and common doesn't mean it is beneficial or constructive.
You may have the freedom to kiss, but if it leads you to lust, coercion and other areas of sin, it is not a constructive way to spend your time.
Instead, the counsel of many Christian advisers is to ask God for guidance to show the direction to follow.
First, some types of kisses are acceptable and even expected.
For devout Christians, the answer boils down to what is in your heart at the time.