Question: "What is an appropriate level of intimacy before marriage?"
Answer: Ephesians 5:3 tells us, "But among you there must not be even a hint of sexual immorality, or of any kind of impurity...because these are improper for God's holy people." Anything that even "hints" of sexual immorality is inappropriate for a Christian. The Bible does not give us a list of what qualifies as a "hint" or tell us what physical activities are approved for a couple to engage in before marriage. However, just because the Bible does not specifically address the issue does not mean God approves of "pre-sexual" activity before marriage. By essence, foreplay is designed to get one ready for sex. Logically then, foreplay should be restricted to married couples. Anything that can be considered foreplay should be avoided until marriage.
If there is any doubt whatsoever whether an activity is right for an unmarried couple, it should be avoided (Romans 14:23). Any and all sexual and pre-sexual activity should be restricted to married couples. An unmarried couple should avoid any activity that tempts them toward sex, that gives the appearance of immorality, or that could be considered foreplay. Many pastors and Christian counselors strongly advise a couple to not go beyond holding hands, hugging, and light kissing before marriage. The more a married couple has to share exclusively between themselves, the more special and unique the sexual relationship in that marriage becomes.