When we say that "in our heart we feel we are called to marriage" we often mean that we feel much more the pull to marriage than to the vocation. That is not uncommon. As a matter of fact, I am uneasy about a vocation if the attraction to marriage is not also there to some degree.

The answer to your question (whether it is prudent or not to start to date this great guy you mention) depends on several things, principally your age and your awareness of your call. I am going to suppose you are at the prudent age for dating.

If you experience no specific attraction towards, or at least curiosity about a vocation I dont think you need to question further. Start dating and see if this is the man God has in mind for you. However, if the thought of a vocation is on your mind, even though it is facing some stiff competition, you have to at least consider that it just may be from God. In this case you would need to test it, and for that you will find a spiritual director to be of great help.

As long as it is possible that God might be calling you, I think it would be wise for you to put off dating while you dedicate some more time to God, and do all you can to favor the growth of a vocation in case you have one.

Don't wait for passively. Find a spiritual director, offer yourself to God in prayer and look into any specific order that attracts you.

God bless,