If your baby does not take to a bottle you could try the following:
Get someone else to offer the bottle
Offer it at a time when your baby is neither starving hungry nor completely full
Feed your baby somewhere apart from where you usually sit, so that he does not assume that he will be getting a breastfeed
Offer the bottle in the dark, so he cannot see it
Warm the teat before offering it to him
Try different brands of teat
If he is old enough, (five or six months) use a spouted beaker rather than a bottle
If he is on solids, add breast milk or formula to his food so that he gets the goodness via another route