10 month old fighting sleep?

My son has been fighting sleep since he was about 4 months old. He will fuss, cry, kick, and squirm until he falls off. For this reason, my husband or I have to hold him in our arms and pat his until he drifts off. If we were to lay him down in his crib awake, he would roll over, crawl to the side, and pull himself up. He then cries his lungs out until he is picked up and "patted" to sleep. I don't want this to become an issue as he gets older, but I don't know what to do. I don't like hearing him cry like that, knowing I can soothe him. We do have a routine at night (diaper, pj's, cuddle time, and then sleep). But, it just seems he would rather stay up and play than sleep, even though he is extremely tired and exhausted. What can I do to help him sleep on his own without having to rock and pat him to sleep every night?