The damage is still dealt fully, even though Worship makes it so your life total can't go under 1. This means you gain the full 4 life from the lifelink creature.
Source: Gatherer rulings
10/4/2004 It reduces your life total to 1, not the damage to 1.
10/4/2004 Worship does not prevent damage. It causes some damage to be
unable to lower your life total. So any damage rendered useless by
Worship was still dealt and is counted by effects that track the
amount of damage done to a player. In addition, Worship does not
prevent loss of life, so loss of life bypasses Worship.