Does it matter which part of the ministry work I do?

No, the particular part of ministry work is not what ultimately counts. Whether a believer plants, waters, or fills another role, God alone gives the increase. Those who plant and water are one, and no worker can take credit for salvation. The calling is to sow the seed faithfully.

Les explains that whether we are the planter, the waterer, or whatever other part of the work we may do, that is not what counts. Neither the one who plants nor the one who waters is anything; God gives the increase. Paul did not take credit even though he planted, and Apollos watered, because God gave the increase. The one who plants and the one who waters are one. No believer can take credit for someone's salvation, since God does the saving. The role of every believer is to sow the seed, sometimes with just a few words or a small statement that makes someone consider eternity. Then God can move in and finish the work of salvation.

1 Corinthians 3:7

So then neither is he that planteth any thing, neither he that watereth; but God that giveth the increase.

Does it matter whether you are the one who plants or the one who waters?

No, it does not ultimately matter whether you plant or water. Both roles are one, and neither is anything by itself, because God alone gives the increase. A believer sows the seed, but God saves. Therefore no one can take credit for salvation; the increase comes from Him.